Chapter 21

EXTERNAL CAUSES OF MORBIDITY

Introduction

Codes for external causes of morbidity are found in Chapter 21. External cause codes classify environmental events and other circumstances as the cause of injury and other adverse effects. Codes in this chapter are always reported as a secondary code with the nature of the condition or injury reported as the first-listed diagnosis. External cause codes are most frequently reported with codes in Chapter 19 Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88). There are also conditions listed in other chapters that may also be due to an external cause. For example, when a condition such as a myocardial infarction is specifically stated as due to or precipitated by strenuous activity, such as shoveling snow, then external cause codes should be reported to identify the activity, place, and external cause status.

While not all third party payers require reporting of external cause codes, they are a valuable source of information to public health departments and other state agencies regarding the causes of death, injury, poisoning, and adverse effects. In fact, more than half of all states have mandated that hospitals collect external cause data using statewide hospital discharge data systems. Another third of all states routinely collect external cause data even though it is not mandated. There are also 15 states that have mandated statewide hospital emergency department data systems requiring collection of external cause data.

External cause of injury codes provide a framework for systematically collecting patient health related information on the external cause of death, injury, poisoning, and adverse effects. These codes define the manner of the death or injury, the mechanism, the place of occurrence of the event, the activity, and the status of the person at the time death or injury occurred. The manner of death or injury refers to whether the cause was unintentional/accidental, self-inflicted, assault, or undetermined. Mechanism describes how the injury occurred, such as a motor vehicle accident, a fall, contact with a sharp object or power tool, or being caught between moving objects. Place identifies where the injury occurred, such as a personal residence, playground, street, or place of employment. Activity indicates the activity of the person at the time the injury occurred such as swimming, running, bathing, or cooking. External cause status is used to indicate the status of the person at the time death or injury occurred such as work done for pay, military activity, or volunteer activity.

The table below lists the ICD-10-CM chapter blocks for external causes.

ICD-10-CM Blocks
V00-V99	Transport Accidents
V00-V09	Pedestrian Injured in Transport Accident
V10-V19	Pedal Cycle Rider Injured in Transport Accident
V20-V29	Motorcycle Rider Injured in Transport Accident
V30-V39	Occupant of 3-Wheeled Vehicle Injured in Transport Accident
V40-V49	Car Occupant Injured Transport Accident
V50-V59	Occupant of Pick-up Truck or Van Injured in Transport Accident
V60-V69	Occupant of Heavy Transport Vehicle Injured in Transport Accident
V70-V79	Bus Occupant Injured in Transport Accident
V80-V89	Other Land Transport Accidents
V90-V94	Water Transport Accidents
V95-V97	Air and Space Transport Accidents
V98-V99	Other and Unspecified Transport Accidents
W00-X58	Other External Causes of Accidental Injury
W00-W19	Slipping, Tripping, Stumbling and Falls
W20-W49	Exposure to Inanimate Mechanical Forces
W50-W64	Exposure to Animate Mechanical forces
W65-W74	Accidental Non-Transport Drowning and Submersion
W85-W99	Exposure to Electric Current, Radiation, and Extreme Ambient Air Temperature and Pressure
X00-X08	Exposure to Smoke, Fire, and Flames
X10-X19	Contact with Heat and Hot Substances
X30-X39	Exposure to Forces of Nature
X52-X58	Accidental Exposure to Other Specified Factors
X71-X83	Intentional Self-Harm
X92-Y08	Assault
Y21-Y33	Event of Undetermined Intent
Y35-Y38	Legal Intervention, Operations of War, Military Operations, and Terrorism
Y62-Y84	Complications of Medical and Surgical Care
Y62-Y69	Misadventures to Patients During Surgical and Medical Care
Y70-Y82	Medical Devices Associated With Adverse Incidents in Diagnostic and Therapeutic Use
Y83-Y84	Surgical and Other medical Procedures as the Cause of Abnormal Reaction of the Patient, or of Later Complication, Without Mention of Misadventure at the Time of the Procedure
Y90-Y99	Supplementary Factors Related to Causes of Morbidity Classified Elsewhere
Note: Block Y90-Y99 includes codes for place of occurrence, activity, and external cause status

Alphabetic Index to External Causes

There is a separate index for external causes in ICD-10-CM. It follows the Table of Drugs and Chemicals.

Chapter Guidelines

Guidelines for Chapter 21 External Causes of Morbidity are provided so that there is standardization in the assignment of these codes. The external causes of morbidity codes should never be sequenced as the first-listed or principal diagnosis.

External cause codes are always secondary codes and can be used in any healthcare setting. External cause codes provide a means of capturing data on injuries, which is used for injury research and the development of prevention strategies.

Most recent guidelines added in 2014 clarify that there is no national requirement for mandatory ICD-10-CM external cause code reporting. Unless a provider is subject to a state-based external cause code reporting mandate or these codes are required by a particular payer, reporting of ICD-10-CM codes in Chapter 20, External Causes of Morbidity, is not required. However, in the absence of a mandatory reporting requirement, providers are encouraged to voluntarily report external cause codes, as they provide valuable data for injury research and evaluation of injury prevention strategies.

General External Cause Coding Guidelines

The general external cause coding guidelines relate to all external cause codes, including those that describe the cause, the intent, the place of occurrence, the activity of the patient, and the patient’s status at the time of the injury. There are more specific guidelines that relate to each particular type of external cause codes. The general guidelines are as follows:

External cause codes may be used with any code in ranges A00.0-T88.9 or Z00-Z99 when the health condition is due to an external cause. The most common health conditions related to external causes are those for injuries in categories S00-T88

•It is appropriate to assign external cause codes to infections and diseases in categories A00-R99 and Z00-Z99 that are the result of an external cause, such as a heart attack resulting from strenuous activity.

•There are multiple types of external cause codes that are used to completely identify the cause, intent, place of occurrence, activity and status for injuries. The majority of external cause codes are assigned for the entire length of treatment for the condition resulting from the external cause. Some of the external cause codes are only reported on the initial visit.

•The appropriate 7th character must be assigned to identify the encounter as the initial encounter, subsequent encounter, or sequela

•Assign as many external cause codes as needed to fully explain each cause. If only one external cause code can be recorded, assign the code most related to the principal diagnosis

•Selection of the appropriate external cause code is guided by the Alphabetic Index to External Causes and by Includes and Excludes notes in the Tabular List

•External cause codes are never the principal or first-listed diagnosis

•Certain external cause codes are combination codes that describe sequential events resulting in an injury, such as a fall from striking against an object. The injury may be due to either or both events. The code assigned should correspond to the sequence of events regardless of which event caused the most serious injury

•No external cause code is required if the external cause and intent are captured by a code from another chapter. Codes for poisoning, adverse effect, and underdosing of drugs, medicaments, and biological substances in categories T36-T50 and toxic effects of substances chiefly nonmedicinal as to source in categories T51-T65 capture both the external cause and the intent.

Place of Occurrence, Activity, and Status Codes

When applicable, place of occurrence (Y92), activity (Y93), and external cause status (Y99) codes are sequenced after the main external cause codes. Regardless of the number of external cause codes assigned to describe the cause generally, only one place of occurrence, one activity, and one external cause status code is assigned. In the rare instance that a new injury occurs during hospitalization, an additional place of occurrence code may be assigned.

Place of Occurrence Guidelines

A code from category Y92 Place of occurrence of the external cause is assigned to identify the location of the patient at the time of injury or other health condition. Place of occurrence codes are secondary codes for use after other external cause codes.

•A place of occurrence code is used only once at the initial encounter for treatment

•7th characters are not used for place of occurrence codes in category Y92

•Only one code from category Y92 is recorded in the medical record unless a new injury occurs during hospitalization, then an additional place of occurrence code may be assigned

•A place of occurrence code is used in conjunction with an activity code from category Y93

•If the place of occurrence is not documented or not applicable, DO NOT assign code Y92.9 Unspecified place or not applicable

Activity Code Guidelines

A code from category Y93 Activity code is assigned to describe the activity of the patient at the time the injury or other health condition occurred.

•An activity code is used only once at the initial encounter for treatment

•Only one code from category Y93 is recorded in the medical record

•An activity code is used with a place of occurrence code from category Y92

•Use an activity code with external cause and intent codes if identifying the activity provides additional information about the event

•Activity codes DO NOT apply to poisonings, adverse effects, misadventures, or sequela

•If the activity is not stated, DO NOT assign code Y93.9 Unspecified activity

External Cause Status Guidelines

A code from category Y99 External cause status should be assigned whenever any other external cause code is assigned for an encounter, including an activity code, except for the events noted below. Guidelines are as follows:

•Assign a code from category Y99 to indicate the work status of the person at the time the event occurred

•The status code indicates that the event occurred during a

•Civilian work activity

•Military work activity

•Non-work activity, such as a student, volunteer, or leisure activity

•Assign a code from category Y99 when applicable with other external cause codes, such as transport accidents or falls

•External cause status codes do not apply to poisoning, adverse effects, misadventures, or late effects

•DO NOT assign a code from category Y99 if no other external cause codes (cause, activity) are applicable to the encounter

•An external cause status code is used only once at the initial encounter for treatment

•Only one code from category Y99 should be recorded in the medical record

•DO NOT assign code Y99.9 Unspecified external cause status if the status is not stated

Reporting Format Limits to the Number of External Cause Codes

If the reporting format limits the number of external cause codes that can be reported, external cause codes should be reported in the following order:

•First report the code for the external cause/intent most related to the principal diagnosis

•If the reporting format allows capture of additional external cause codes, next report the cause/intent, including medical misadventures of additional events

•Codes for the above described external cause(s)/intent(s) should be reported rather than the codes for place, activity, or external cause status

Multiple External Cause Coding Guidelines

Some external cause circumstances may require that more than one external cause code be reported to fully describe the external cause of an illness, injury, or poisoning. Sequencing of external cause codes are prioritized as follows:

•For two or more events causing separate injuries, the external cause codes should be assigned in the following order:

–External cause codes for child and adult abuse take priority over all other external cause codes

–External cause codes for terrorism events take priority over all other external cause codes except child and adult abuse

–External cause codes for cataclysmic events take priority over all other external cause codes except child and adult abuse, and terrorism

–External cause codes for transport accidents take priority over all other external cause codes except child and adult abuse, terrorism, and cataclysmic events

•Activity and external cause status codes are assigned following all causal (intent) external cause codes

•The first-listed external cause code should correspond to the cause of the most serious diagnosis due to an assault, accident, or self-harm following the order of hierarchy listed above

Child and Adult Abuse Guidelines

Adult and child abuse and neglect are classified as assault. Assault codes may be used to indicate the external cause of an injury resulting from the confirmed abuse. For confirmed cases of abuse, neglect, and maltreatment, when the perpetrator is known, a code from Y07 Perpetrator of maltreatment and neglect should accompany any other assault codes.

Unknown or Undetermined Intent Guidelines

The following guidelines apply to assignment of codes for unknown or undetermined intent:

•If the intent (accident, self-harm, assault) of the cause of an injury or other condition is unknown or unspecified, code the intent as accidental

•All transport accident categories assume accidental intent

•A code for undetermined intent is assigned only when the documentation in the medical record specified that the intent cannot be determined

Sequelae (Late Effects) of External Cause Guidelines

Sequelae are reported using the code for the external cause with the 7th character extension ‘S’ for sequela:

•Use for any condition described as a late effect or sequela resulting from a previous injury

•A sequela external cause code should never be used with a related current nature of injury code

•Use a sequela external cause code for subsequent visits when a late effect of the initial injury is being treated

•Do not use a late effect external cause code for subsequent visits for follow-up care (e.g., to assess healing or to receive rehabilitative therapy) of the injury or poisoning when no late effect of the injury has been documented

Terrorism Guidelines

External cause codes for terrorism are used to identify injuries resulting from the unlawful use of force or violence against persons or property to intimidate or coerce a government, the civilian population, or any segment thereof, in furtherance of a political or social objective. Terrorism external cause codes are assigned when the cause of an injury is identified by the Federal Government (FBI) as terrorism and should be assigned as follows:

•The first listed external cause code should be a code from category Y38 Terrorism

•Use an additional code from category Y92 to identify the place of occurrence

•More than one code from category Y38 may be assigned if the injury is the result of more than one mechanism of terrorism

When the cause of injury is the result of suspected terrorism:

•DO NOT assign a code from category Y38

•Suspected terrorism is classified as assault

For conditions occurring subsequent to the terrorist event:

•Assign code Y38.9 Terrorism, secondary effects

•DO NOT assign code Y38.9 for conditions that are due to the initial terrorist act

•Code Y38.9 may be assigned with another code from category Y38 when there is an injury due to the initial terrorist event and an injury that is a subsequent result of the terrorist event

General Documentation Requirements

Increased granularity in ICD-10-CM codes requires specific documentation of cause, intent, place of occurrence, and activity at the time of the injury or other health condition. With the ICD-10-CM code set, separate external cause codes are not required for poisoning, adverse effects, or underdosing of drugs and other substances (T36-T50), or for toxic effect of nonmedicinal substances (T51-T65), since the external cause is now captured in a combination code from Chapter 19. External cause codes do require a 7th character to identify the episode of care. The 7th characters used in Chapter 20 are the same as those used in Chapter 19 and the characters have the same definitions. The characters and definitions are as follows:

AInitial encounter. This is the period when the patient is receiving active treatment for the injury, poisoning, or other consequences of an external cause. An ‘A’ may be assigned on more than one claim.

DSubsequent encounter. This is an encounter after the active phase of treatment when the patient is receiving routine care for the injury or poisoning during the period of healing or recovery.

SSequela. The 7th character extension ‘S’ is assigned for complications or conditions that arise as a direct result of an injury.

Classification of Codes

Reviewing the code blocks provides a good overview of how the general classifications of external causes are arranged. More detailed information on classification of codes is provided in the code specific examples that follow.

Combination Codes

As was discussed in Chapter 19 Injury, Poisoning, and Other Consequences of External Causes, there are combination codes for two blocks of codes including: T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments, and biological substances; and T51-T65 Toxic effects of substances chiefly nonmedicinal as to source. These combination codes identify both the substance and the intent which includes accidental (unintentional), intentional self-harm, assault, and undetermined for poisoning and toxic effects of nonmedicinal substances. This means that there are no external cause codes for these conditions in the external cause chapter.

Code-Specific Documentation Requirements

Many examples of external cause coding were provided in Chapter 19 covering injury and poisoning. Some of the same scenarios are used in this chapter but the focus of the discussion here is on the documentation elements required to capture the most specific external cause codes. In this section, ranges of codes used to describe the same type of accidents are first discussed and then a specific example is provided of the documentation elements for a specific accident category or subcategory in that range of codes.

Accidental Falls

The external cause code categories that capture falls are found in block W00-W19 Slipping, tripping, stumbling, and falls. Category W09 Fall on and from playground equipment has three specific codes—for slide (W09.0-), swing (W09.1-), and jungle gym (W09.2-) with a fourth code for other playground equipment (W09.8-). Another example of code specificity is found in category W13 Fall from, out of or through building or structure. Codes in category W13 are specific to balcony (W13.0), bridge (W13.1-), roof (W13.2-), through floor (W13.3-), and from, out of, or through window (W13.4-). There are additional codes for fall from, out of or through other building or structure (W13.8-) and fall from, out of or through building, not otherwise specified (W13.9-).

Codes for falls also capture external causes of accidental injury due to jumping or diving into water in addition to falling into water. Codes in categories W00-W19 are specific to accidental fall injuries. Falls involving an assault are found in categories Y01-Y02. Falls involving assault are specific to pushing from high place (Y01) and pushing in front of moving object (Y02).

Other Fall from One Level to Another

An example of the coding and documentation requirements for other fall from one level to another along with some of the ICD-10-CM external cause codes is provided below.

Coding and Documentation Requirements

Identify other fall from one level to another:

•Fall down embankment

•Fall from/out of grocery cart

•Fall from tree

•Other fall from one level to another, which includes

–Fall from cherry picker

–Fall from lifting device

–Fall from mobile elevated work platform

–Fall from sky lift

Identify episode of care:

•Initial

•Subsequent

•Sequela

ICD-10-CM Code/Documentation
W14.-	Fall from tree
W17.81-	Fall down embankment (hill)
W17.82-	Fall from (out of) grocery cart
W17.89-	Other fall from one level to another
Note: A 7th digit is required to identify the episode of care.

Documentation and Coding Example

Thirty-nine-year-old male presents to ED with c/o moderate to severe pain in his back after falling approximately 15 feet from a boulder while rock climbing. Accident occurred approximately 2 hours ago. Patient is a well-developed, well-nourished male who looks younger than his stated age. He is muscular and very tan. He states he is a professional guide leading hiking tours and rock climbing expeditions. The accident today occurred in his leisure time on a familiar rock face and was witnessed by friends. As he descended from the top of the rock, his equipment malfunctioned and he dropped rapidly landing with a hard jolt upright on both legs. He felt an immediate sharp pain in the mid back which is relieved somewhat by lying flat. He denies pain in his hips, knees, or ankles and was able to hike approximately 0.5 miles to a vehicle. On examination: Temperature 99 degrees, HR 72, RR 12, BP 114/60. Skin warm, slightly diaphoretic, outdoor temperature is in upper 80s. O2 saturation on RA 96%. PERRL, oriented x 3. No cervical spine tenderness and cranial nerves are grossly intact. Motor and sensory function is intact to upper extremities. Breath sounds clear and equal bilaterally, HR regular, no murmur or muffling of heart sounds appreciated. No visual deformities to spine but there is exquisite tenderness with muscle guarding at level of T10 to L4. There is no sign of crepitus. He has limited ROM when attempting flexion, extension, and rotation of spine due to pain. There are no neurological deficits in lower extremities. IV started in left forearm, D5 LR infusing. Medicated for pain with MS 2 mg IV push with good relief. AP and lateral spine x-rays reveal a possible wedge compression fracture at T12. CT confirms wedge compression fracture involving the anterior column at T12. Orthopedic consult obtained. Patient fitted with TLSO brace and discharged home with oral narcotic pain medication and instructions to schedule a follow-up in orthopedic clinic in 1 week.

Diagnosis Code(s)

S22.080A	Wedge compression fracture of T11-T12 vertebra, initial encounter for closed fracture
W17.89XA	Other fall from one level to another, initial encounter
Y93.31	Activity, mountain climbing, rock climbing, and wall climbing
Y92.838	Other recreation area as the place of occurrence of the external cause
Y99.8	Other external cause status

Coding Note(s)

There is no specific code for a fall from a boulder so code W17.89xA is assigned to identify the fall from one level to another and the episode of care as the initial encounter. The code for the place of occurrence is more specific, identifying the place as “other recreation area.” Y99.8 Other external cause status, which includes leisure activity, is used instead of Y99.0 Civilian activity done for income or pay, because the injury occurred during a leisure activity.

Assault Injuries

Injuries caused by an assault are classified in block X92-Y09. The Includes note under assault lists homicide. There are separate codes for various types of firearms including: handgun, rifle, shotgun, and larger firearm. Examples of codes classified in this code block also include assaults by drowning or submersion; explosive material; smoke, fire, and flames; steam, hot vapors, and hot objects; sharp or blunt objects; pushing from a high place; pushing or placing victim in front of a moving object; motor vehicle; and bodily force. Also included in this code block are codes that identify the perpetrator of an assault classified as maltreatment or neglect (Y07). Codes in category Y07 are to be used only in cases of confirmed abuse which is coded to category T74 Adult and child abuse, neglect, and other maltreatment, confirmed.

The example used in the scenario below is an assault by a sharp object. The coding and documentation requirements and code comparisons for this type of scenario are listed below.

Coding and Documentation Requirements

Identify the sharp object:

•Knife

•Glass

•Sword/dagger

•Other sharp object

•Unspecified sharp object

Identify the episode of care:

•Initial encounter

•Subsequent encounter

•Sequela

Assault with Sharp Object

ICD-10-CM Code/Documentation
X99.0-	Assault by sharp glass
X99.1-	Assault by knife
X99.2-	Assault by sword or dagger
X99.8-	Assault by other sharp object
X99.9-	Assault by unspecified sharp object

Documentation and Coding Example

Patient is a 21-year-old male who walks into ED with a stab wound to the abdomen. He states he was at work attempting to mediate a dispute between two employees at his family’s restaurant when the stabbing occurred. On examination, this is a soft spoken, slightly built young man holding a bloody towel to the right abdomen. He is alert and oriented. HR 100, RR 16, BP 98/60. There is a single wound measuring 2 cm in the RUQ, which is not actively bleeding at this time. He states the weapon used was a small paring knife with a blade not more than 3 inches long. Abdominal examination is relatively benign except for the wound and mild tenderness to palpation in RUQ. Breath sounds are clear, equal bilaterally. HR regular with NSR on monitor. IV started in right forearm, blood drawn for CBC, Chemistry Panel, PT, PTT, Type and hold. Flat plate of abdomen is negative for free air. FAST shows some accumulation of fluid in the RUQ along the edge of the liver. Patient is hemodynamically stable. Decision made to take him to CT for abdominal scan to r/o or establish intra-peritoneal injury. Spiral CT with contrast revealed a Grade 2 liver injury with a 1.5 cm parenchymal laceration and a 1.5 cm thick subcapsular/parenchymal hematoma. Patient will be admitted to ICU for observation. Wound irrigated, closed in layers around a drain. He is started on broad spectrum antibiotics. NPO. Transferred to unit in stable condition.

ICU Note: Patient stable overnight. Repeat CT shows no change in hematoma size. Minimal serosanguinous fluid returning from drain, the wound edges are slightly red but suture line is clean. Abdomen soft with bowel sounds present in all quadrants. Pain is localized at the site of the wound and has been well controlled with IV Morphine. Started clear liquid diet and advance as tolerated. Up in a chair, advance activity as tolerated. He is transferred to surgical floor for continued observation.

Floor Note Day 1: Continues to make good recovery. Pain controlled on oral Vicodin. Tolerating soft diet, ambulates to BR. IV heplocked. Continues on antibiotics. Wound healing well, drain removed. Repeat CT ordered for tomorrow. If no change in hematoma size, he will be discharged.

Floor Note Day 2: Repeat CT shows subcapsular/parenchymal hematoma to be resolving, size is now 1 cm thick. He is discharged home with oral Vicodin and antibiotics. He will be seen in Surgical Clinic in 5 days for wound check.

Diagnosis Code(s)

S36.115A	Moderate laceration of liver, initial encounter
S31.630A	Puncture wound without foreign body of abdominal wall, right upper quadrant with penetration into peritoneal cavity, initial encounter
X99.1XXA	Assault by knife, initial encounter
Y92.511	Restaurant or café as the place of occurrence of the external cause
Y99.0	Civilian activity done for income or pay

Coding Note(s)

The code for the cause and intent is specific to an assault with a knife. The place of occurrence is specific to a restaurant or café. The patient was at work, so the external cause status is a civilian activity done for income or pay.

Natural and Environmental Accidents

Some of the external causes listed as exposure to forces of nature are listed in Chapter 19 Injury, Poisoning, and Certain Other Consequences of External Causes. External cause codes in this chapter are combination codes that identify the injury or health condition and the external cause. Codes that are listed in Chapter 19 include:

•Bites and stings by venomous animals and insects, and poisoning by toxic plants in category T63 Toxic effect of contact with venous animals and plants

•Abandonment or neglect of helpless individuals in category T74 Adult and child abuse, neglect, and other maltreatment

•Effects of lightning and motion sickness in category T75 Other and unspecified effects of other external causes

Codes for external causes of injury caused by nonvenomous animals due to mechanical forces such as bites, scratches, or being struck or gored by the animal are listed in categories W53-W64. All of the external causes related to forces of nature are listed in categories X30-X39. External causes of injury and health conditions classified in this code block include: excessive natural heat and cold; sunlight; earthquakes, avalanches, and volcanoes; landslides and other earth movements; cataclysmic storms such as hurricanes, tornadoes, blizzards, and dust storms; tidal waves and floods; and exposure to other forces of nature.

Coding and Documentation Requirements

Identify the animal:

•Alligator

•Amphibians

–Frogs

–Toads

–Other nonvenomous amphibians

•Arthropod/insect

•Birds

–Chicken

–Duck

–Goose

–Psittacines

»Macaw

»Parrot

»Other psittacines

–Turkey

–Other birds

•Crocodile

•Mammal (other than marine mammal)

–Cat

–Dog

–Hoof stock

»Cow

»Horse

»Other hoof stock

–Pig

–Raccoon

–Rodent

»Mouse

»Rat

»Squirrel

»Other rodent

–Other nonvenomous mammal

•Marine animal

–Marine mammal

»Dolphin

»Orca

»Sea lion

»Other marine mammal

–Fish

»Shark

»Other fish

–Other nonvenomous marine animal

•Reptiles

–Lizards

–Snakes

–Turtles

–Other nonvenomous reptile

•Other/unspecified nonvenomous animal

Identify type of contact with nonvenomous animal:

•Bite

•Crushed by

•Pecked

•Scratch

•Struck by

•Other type of contact causing injury or a health condition, which includes contact with

–Feces

–Saliva

–Urine

Identify episode of care:

•Initial encounter

•Subsequent encounter

•Sequela

External Cause – Contact with Dog

ICD-10-CM Code/Documentation
W54.0-	Bitten by dog
W54.1-	Struck by dog
W54.8-	Other contact with dog
Note: A 7th digit is required to identify the episode of care.

Documentation and Coding Example

Patient is a 4-year-old Caucasian male bought to ED by his parents after being bitten by the family dog. There were no adult witnesses to the attack, but older children admit that they placed the boy on the dog’s back so he could “ride” her. The dog yelped and turned, biting him on the right arm. Crying but fairly cooperative, young boy is examined while being held by his father. The right forearm has a 4 cm long jagged wound consistent with a dog bite. ROM, sensation, and circulation intact to fingers and hand. There is some difficulty with pronation and supination of the forearm suggestive of brachioradialis muscle or tendon injury. Wound infiltrated with 2% Lidocaine with epinephrine and child fell asleep soon afterward. Wound copiously irrigated with dilute betadine and NS. The wound extends into and partially severs the brachioradialis tendon near insertion at the distal styloid process of the radius. Radial nerve is identified and appears to be intact. There are no large vascular structures damaged. The tendon is repaired with 3-0 Chromic followed by a 2-layer wound closure. Sterile dressing and soft short arm splint applied. Patient woke up at the end of the procedure, remains quiet and cooperative. He denies pain at this time. Parents are given a prescription for Tylenol with codeine, instructed to keep dressing and splint dry. Patient has a follow up appointment in surgical clinic in 5 days.

Diagnosis Code(s)

S51.851A	Open bite of right forearm, initial encounter
S56.221A	Laceration of other flexor muscle, fascia, and tendon at forearm level, right arm, initial encounter
W54.0XXA	Bitten by dog, initial encounter
Y92.009	Unspecified place in unspecified non-institutional (private) residence as the place of occurrence of the external cause
Y93.89	Activity, other specified
Y99.8	Other external cause status

Coding Note(s)

There is a specific code for a dog bite as the cause of the wound, which is identified additionally as the initial encounter. Although the place of occurrence was at home, a noninstitutional private residence, there is not enough information to assign a specific code because the documentation does not state whether the injury occurred in a single-family residence, an apartment, or other type of private residence, nor is the room or area of the residence where the injury occurred identified. An activity is provided but there is not a specific code for that activity. Since the patient is a child and was playing, the code for other external cause status is reported.

Transport Accidents

External cause codes for transport accidents are found in categories V00-V99 and the definition of a transport accident is any accident involving a device designed primarily for, or being used at the time primarily for, conveying persons or goods from one place to another. In order to assign codes accurately for transport accidents, definitions related to transport accidents, which are found under the code block (V00-V99), must be applied in order to select the appropriate code.

In ICD-10-CM, code block V00-V99 for transport accidents is structured into 12 groups as follows:

•V00-V09 Pedestrian Injured in Transport Accident

•V10-V19 Pedal Cycle Rider Injured in Transport Accident

•V20-V29 Motorcycle Rider Injured in Transport Accident

•V30-V39 Occupant of Three-Wheeled Vehicle Injured in Transport Accident

•V40-V49 Car Occupant Injured Transport Accident

•V50-V59 Occupant of Pick-up Truck or Van Injured in Transport Accident

•V60-V69 Occupant of Heavy Transport Vehicle Injured in Transport Accident

•V70-V79 Bus Occupant Injured in Transport Accident

•V80-V89 Other Land Transport Accidents

•V90-V94 Water Transport Accidents

•V95-V97 Air and Space Transport Accidents

•V98-V99 Other and Unspecified Transport Accidents

The first nine groups (V00-V89), excluding category V00 for pedestrian conveyance accidents, relate to land-transport accidents and reflect the victim’s mode of transport. The groups are then subdivided into categories to identify the victim’s counterpart or the type of event. The type of vehicle of which the injured person is an occupant is identified in the first two characters of the code since this is seen as the most important factor to identify for prevention purposes. To be classified as a transport accident, the vehicle involved must be moving or running or in use for transport purposes at the time of the accident.

In the section below, the documentation elements for a motor vehicle/pedestrian accident are described.

Coding and Documentation Requirements

Identify the mode of transport of the accident victim as a pedestrian in the motor vehicle/pedestrian accident and further specify the mode of pedestrian conveyance:

•On foot

•On roller skates

•On standing micromobility conveyance

•On skateboard

•With other conveyance

Identify the victim’s (patient’s) counterpart in the motor vehicle/pedestrian accident:

•2 or 3-wheeled vehicle

•Car, pick-up truck, or van

•Heavy transport vehicle or bus

•Railway train or vehicle

Identify type of accident:

•Non-traffic

•Traffic

•Unspecified

Identify episode of care:

•Initial

•Subsequent

•Sequela

Use additional codes to identify place of occurrence, activity, and external cause status as appropriate.

Pedestrian/Motor Vehicle Accident

Note: a 7th character to identify the episode of care is required

ICD-10-CM Code/Documentation
Two- or Three-Wheeled Motor Vehicle
V02.00-	Pedestrian on foot injured in collision with two- or three-wheeled motor vehicle in nontraffic accident
V02.01-	Pedestrian on roller-skates injured in collision with two- or three-wheeled motor vehicle in nontraffic accident
V02.031-	Pedestrian on standing electric scooter injured in collision with two- or three-wheeled motor vehicle in nontraffic accident
V02.038-	Pedestrian on other standing micro-mobility pedestrian conveyance injured in collision with two- or three-wheeled motor vehicle in nontraffic accident
V02.02-	Pedestrian on skateboard injured in collision with two- or three-wheeled motor vehicle in nontraffic accident
V02.09-	Pedestrian with other conveyance injured in collision with two- or three-wheeled motor vehicle in nontraffic accident
V02.10-	Pedestrian on foot injured in collision with two- or three-wheeled motor vehicle in traffic accident
V02.11-	Pedestrian on roller skates injured in collision with two- or three-wheeled motor vehicle in traffic accident
V02.12-	Pedestrian on skateboard injured in collision with two- or three-wheeled motor vehicle in traffic accident
V02.131-	Pedestrian on standing electric scooter injured in collision with two- or three-wheeled motor vehicle in traffic accident
V02.138-	Pedestrian on other standing micro-mobility pedestrian conveyance injured in collisionwith two- or three-wheeled motor vehicle in traffic accident
V02.19-	Pedestrian with other conveyance injured in collision with two- or three-wheeled motor vehicle in traffic accident
V02.90-	Pedestrian on foot injured in collision with two- or three-wheeled motor vehicle, unspecified whether traffic or nontraffic accident
V02.91-	Pedestrian on roller skates injured in collision with two- or three-wheeled motor vehicle, unspecified whether traffic or nontraffic accident
V02.92-	Pedestrian on skateboard injured in collision with two- or three-wheeled motor vehicle, unspecified whether traffic or nontraffic accident
V02.931-	Pedestrian on standing electric scooter injured in collision with two- or three wheeled motor vehicle, unspecified whether traffic or nontraffic accident
V02.938-	Pedestrian on other standing micro-mobility pedestrian conveyance injured in collision with two- or three wheeled motor vehicle, unspecified whether traffic or nontraffic accident
V02.99-	Pedestrian with other conveyance injured in collision with two- or three-wheeled motor vehicle, unspecified whether traffic or nontraffic accident
Other and Unspecified Vehicles
V09.00-	Pedestrian injured in nontraffic accident involving unspecified motor vehicles
V09.01-	Pedestrian injured in nontraffic accident involving military vehicle
V09.09-	Pedestrian injured in nontraffic accident involving other motor vehicles
V09.20-	Pedestrian injured in traffic accident involving unspecified motor vehicles
V09.21-	Pedestrian injured in traffic accident involving military vehicles
V09.29-	Pedestrian injured in traffic accident involving other motor vehicles

Documentation and Coding Example

ED Note: Patient is a fifty-three-year-old female involved in a pedestrian vs. van accident. Patient was crossing the street in a marked crosswalk when she was struck by a van making a left turn. The van struck the patient on her right side with the impact propelling her into the air, landing approximately 10 feet away on the pavement. She is complaining of pain in her right hip. On examination, this is a well-developed, well-nourished female who is alert and oriented x 3. HR 94, RR 16, BP 150/86. O2 saturation 97 % on oxygen at 2 L/m via NC. PERRL. Breath sounds clear, equal bilaterally, HR regular without murmur or muffling. No abdominal or flank tenderness, bladder is not palpated. There is bruising over the right hip area with visual limb length inequality. Bedside US reveals no free fluid in peritoneum. Foley catheter placed with some difficulty due to hip pain and deformity. Urine returned is dark yellow, dipstick negative for blood. Blood drawn for CBC, electrolytes, PT, PTT, Type and hold. EKG obtained. AP and oblique views of pelvis reveal a transverse-posterior wall fracture of the right acetabulum. CT scan of pelvis and abdomen R/O intra-abdominal organ injury and enhanced 3D reconstruction shows a nondisplaced transverse acetabular fracture with an associated moderately displaced posterior wall fracture on the right. Care of patient is assumed by orthopedic team as patient awaits transfer to OR.

Diagnosis Code(s)

S32.461A	Displaced associated transverse-posterior fracture of right acetabulum, initial encounter for closed fracture
V03.10XA	Pedestrian on foot injured in collision with car, pickup truck or van in traffic accident, initial encounter
Y92.410	Unspecified street and highway as the place of occurrence of the external cause

Coding Note(s)

The external cause code provides more information about the type of accident and the injured person. The code captures information about the pedestrian by identifying that the pedestrian was on foot and not using a pedestrian conveyance. It also identifies the type of vehicle specifically and identifies the encounter as the initial encounter. A second external cause code is assigned to identify the place of occurrence as an unspecified street/highway. Neither the activity nor the patient’s work status is documented, so no codes are assigned from categories V93 or V99.

Place of Occurrence

Place of occurrence codes are found in category Y92. For a non-institutional residence there are subcategories for single family home, mobile home, apartment (includes condominium), boarding house, other non-institutional residence, and unspecified non-institutional residence. Specific codes within these subcategories identify the specific room or areas of the house or premises where the injury or health condition occurred, such as the kitchen, dining room, bathroom, bedroom, driveway, garage, swimming pool, garden/yard, other specified place, or unspecified place. The greater specificity extends to all places of occurrence including institutional residences, schools, sports and athletic areas, streets and highways, trade and service areas, industrial and construction areas, farms, and other places.

Coding and documentation requirements are provided below for a home or noninstitutional residence as the place of occurrence.

Coding and Documentation Requirements

Identify non-institutional (private) residence:

•Apartment

•Boarding house

•Mobile home

•Single family house

•Other specified non-institutional residence

•Unspecified non-institutional residence

Identify room or area of premises where accident occurred:

•Room

–Bathroom

–Bedroom

–Dining room

–Kitchen

•Other specific area

–Driveway

–Garage

–Garden/yard

–Swimming pool

•Other specified place of residence or premises

•Unspecified place

Single-Family Noninstitutional House as Place of Occurrence

ICD-10-CM Code/Documentation
Y92.010	Kitchen of single-family (private) house as the place of occurrence of the external cause
Y92.011	Dining room of single-family (private) house as the place of occurrence of the external cause
Y92.012	Bathroom of single-family (private) house as the place of occurrence of the external cause
Y92.013	Bedroom of single-family (private) house as the place of occurrence of the external cause
Y92.014	Private driveway to single-family (private) house as the place of occurrence of the external cause
Y92.015	Private garage of single-family (private) house as the place of occurrence of the external cause
Y92.016	Swimming pool in single-family (private) house or garden as the place of occurrence of the external cause
Y92.017	Garden or yard in single-family (private) house as the place of occurrence of the external cause
Y92.018	Other place in single-family (private) house as the place of occurrence of the external cause
Y92.019	Unspecified place in single-family (private) house as the place of occurrence of the external cause

Documentation and Coding Example

Twenty-three-year-old Black male employed as a gardener on a private estate presents to Urgent Care Clinic with a right shoulder injury sustained about 6 hours ago. He reports that he fell approximately 5 feet off a ladder while trimming hedges, landing on his outstretched right arm and hand. He describes a “popping” feeling in the shoulder followed by numbness in the arm and hand. He was able to move the extremity after a few minutes and the numbness subsided in approximately one hour, but the shoulder has continued to feel loose all day. PMH includes asthma for which he takes Singulair, Advair daily and Albuterol when needed; and TB treated with INH seven years ago. On examination, this is a soft spoken, slightly built, thin young man. Temperature 97.4, HR 62, RR 14, BP 116/70. Alert and oriented x 3, PERRL, patient denies striking head, neck, or back in the fall. Heart rate regular without murmur, breath sounds have a few expiratory wheezes but otherwise clear and equal bilaterally. Left upper extremity is normal in appearance. Right clavicle has slight prominence but otherwise normal contour, there is no shoulder sag. Moderate point tenderness is localized over the AC joint which can be easily manipulated out of position. There are no obvious neurovascular deficits. X-rays obtained including AP and lateral views of shoulder, lateral projection of scapula and weight bearing view (AP projection w/15 lb. weight). No fractures visible and no obvious dislocation of clavicle or humerus.

Impression: Subluxation of right acromioclavicular joint.

Treatment: Patient is fitted with a sling which can be worn for comfort. He is instructed to ice shoulder x 20 minutes, 3-4 x day and may continue with exercise/activity as tolerated. He is prescribed Ibuprofen 600 mg TID for pain. He will F/U with PMD in one week with possible referral to orthopedist and/or physical therapy for strengthening exercises if the right shoulder joint continues to feel loose.

Diagnosis Code(s)

S43.111A	Subluxation of right acromioclavicular joint, initial encounter
W11.XXXA	Fall on and from ladder, initial encounter
Y92.017	Garden or yard in single-family (private) house as the place of occurrence of the external cause
Y93.H2	Activity, gardening and landscaping
Y99.0	Civilian activity done for income or pay

Coding Note(s)

ICD-10-CM codes are assigned for the external cause, place of occurrence, activity, and external cause status. The external cause is a fall from a ladder. The place of occurrence is the garden/yard of a single family private residence. The activity the patient was performing at the time of the fall is gardening and landscaping and this activity was being done for pay, so the external cause status is the code for civilian activity done for income or pay.

Summary

Even though external cause codes are not required on all claims or by all payers, they do provide valuable information related to the cause, intent, place, activity, and work status of the patient at the time of the injury. Codes for cause, intent, and place are specific in ICD-10-CM which requiring precise documentation by the physician. It is particularly important to document sufficient detail about the external cause of injury when it results in an emergency department visit or an inpatient stay because the majority of states either mandate or routinely collect external cause data for these two places of service.

Chapter 21 Quiz

1.What external cause is not reported with a cause code from Chapter 21 External Causes of Morbidity, in ICD-10-CM?

a.Accidental fall

b.Accidental drowning

c.Unintentional poisoning

d.Assault by a handgun

2.If the documentation does not identify the activity of the patient that resulted in the injury and it is not possible to query the provider, what is reported in ICD-10-CM?

a.No activity code is reported

b.Code Y93.9 Activity unspecified is reported

c.Code Y93.89 Activity other specified is reported

d.Code Y99.9 Unspecified external cause status is assigned

3.Intentional poisoning with barbiturates reported with code T42.3X2 requires an additional code from block X71-X83 to indicate self-harm.

a.True

b.False

4.When the intent of an injury or another condition resulting from an external cause is not documented or not known, how should the intent be reported?

a.No intent code is assigned

b.It is reported with a code for undetermined intent

c.It depends on the other circumstances related to the injury or other condition

d.It is reported as accidental intent

5.Code block V00-V99 is structured into 12 groups. How are land transport accident codes categorized?

a.The type of accident is categorized, such as a two-car collision, roll-over, or other type of accident.

b.Categories identify the mode of transportation of the victim and the victim’s counterpart (vehicle) or the type of event.

c.Categories first designate the accident as a traffic or nontraffic transport accident and then designate the victim.

d.Categories first identify the type of vehicle or vehicles involved in the accident such as auto-pedestrian, car-bus, or single car accident.

6.Identify the true statement about place of occurrence codes.

a.A place of occurrence code is required for all injuries and other health conditions resulting from an external cause.

b.A place of occurrence code requires a 7th character extension to identify the episode of care.

c.A place of occurrence code is reported only once at the initial encounter for treatment.

d.A place of occurrence code is a supplemental code and is not reported unless requested by the payer.

7.The external cause code for a dog bite is found in what block of codes?

a.Exposure to forces of nature (X30-X39)

b.Exposure to inanimate mechanical forces (W20-W49)

c.S and T codes that describe open wounds (S00-T88)

d.Exposure to animate mechanical forces (W50-W64)

8.External cause codes for land transport accidents V00-V09 capture what information related to pedestrians?

a.Whether the pedestrian is on foot or using a pedestrian conveyance

b.The place of occurrence

c.The external cause status

d.All of the above

9.What type of falls are classified in categories W00-W19 Slipping, tripping, stumbling, and falls?

a.Accidental falls

b.Falls involving assault

c.Intentionally jumping from a high place

d.Falls resulting from being pushed from a high place

10.Identify the false statement regarding external cause codes.

a.External cause codes are never the principal or first listed diagnosis

b.Only one external cause code may be reported for a specific injury or episode of care

c.External cause codes may be used with any code in ranges A00.0-T88.9 or Z00-Z99 when the health condition is due to an external cause

d.External cause codes are assigned for the entire length of treatment for the condition resulting from the external cause

Chapter 21 Answers and Rationales

1.What external cause is not reported with a code from Chapter 20 External Causes of Morbidity, in ICD-10-CM?

c.Unintentional poisoning

Rationale: Both the cause and intent of an unintentional poisoning are now captured with a combination code from Chapter 19 Injury, Poisoning, and Certain Other Consequences of External Causes, so no accidental poisoning codes are reported from Chapter 20.

2.If the documentation does not identify the activity of the patient that resulted in the injury and it is not possible to query the provider, what is reported in ICD-10-CM?

a.No activity code is reported

Rationale: Coding guideline I.C.20.c states “DO NOT assign code Y93.9 Unspecified activity, if the activity is not stated.” This means that if the activity is not documented and the physician cannot be queried, no activity code is reported.

3.Intentional poisoning with barbiturates reported with code T42.3X2 requires an additional code from block X71-X83 to indicate self-harm, True or false?

b.False

Rationale: Poisoning codes have a 5th or 6th character that already identifies intent. Coding guideline I.C.20 states that no external cause code from chapter 20 is needed if the external cause and intent are included in a code from another chapter.

4.When the intent of an injury or another condition resulting from an external cause is not documented or not known, how should the intent be reported?

d.It is reported as accidental intent

Rationale: Coding guideline I.C.20.i states “If the intent (accident, self-harm, assault) of the cause of an injury or other condition is unknown or unspecified, code the intent as accidental intent.” The code for undetermined intent is only assigned when documentation in the medical record states that the intent cannot be determined.

5.Code block V00-V99 is structured into 12 groups. How are land transport accident codes categorized?

b.Categories identify the mode of transportation of the victim and the victim’s counterpart (vehicle) or the type of event.

Rationale: According to the note under the code block Transport Accidents V00-V99, land accident categories identify the victim’s mode of transport first and then identify the victim’s counterpart or the type of event. This can be verified by reviewing the code categories for land transport accidents. For example, if the injured person is a bicyclist (pedal cycle rider) who was hit by a car, a code from category V13 Pedal cycle rider injured in collision with car, pick-up truck or van is reported. This category identifies the victim as the pedal cycle rider and the victim’s counterpart as a car, pick-up truck, or van.

6.Identify the true statement about place of occurrence codes.

c.A place of occurrence code is reported only once at the initial encounter for treatment.

Rationale: Place of occurrence codes are reported only once at the initial encounter for treatment. Place of occurrence codes are not required for all injuries or other health care conditions resulting from an external cause. For example, place of occurrence codes are not required for poisoning, adverse effects, and underdosing of drugs. Place of occurrence codes do not require a 7th character for episode of care. Place of occurrence codes may be required by the state for certain care settings (emergency department and inpatient) even if the payer does not require reporting of external cause codes.

7.The external cause code for a dog bite is found in what block of codes?

d.Exposure to animate mechanical forces (W50-W64)

Rationale: The external cause dog bite is classified as exposure to animate mechanical forces (W50-W64). The injury would be reported with a code from categories S00-T88, but codes for bites in the injury chapter do not identify the external cause.

8.External cause codes for land transport accidents V00-V09 capture what information related to pedestrians?

a.Whether the pedestrian is on foot or using a pedestrian conveyance

Rationale: ICD-10-CM external cause codes for land transport accidents involving pedestrians capture information on whether the pedestrian is on foot, on roller-skates, on a skateboard, or using another type of pedestrian conveyances well as the type of vehicle is captured. The external cause codes for the transport do not capture the place of occurrence or the external cause status to capture that information, additional codes are required from category Y92 and Y99.

9.What type of falls are classified in categories W00-W19 Slipping, tripping, stumbling, and falls?

a.Accidental falls

Rationale: Codes in categories W00-W19 are specific to accidental injuries. Falls involving an assault are found in categories Y01-Y02. Falls involving assault are specific to pushing from a high place (Y01) and pushing in front of a moving object (Y02). Falls involving self-harm are found in categories (X80-X81).

10.Identify the false statement regarding external cause codes.

b.Only one external cause code may be reported for a specific injury or episode of care

Rationale: Coding guideline I.C.20.a.4 state “Assign as many external cause codes as necessary to fully explain each cause. If only one external cause code can be recorded, assign the code most related to the principal diagnosis.”