1. ICD 10 Guidelines on External Cause Codes
Presented by Ashley Yawn, BS, CPC
April 17, 2018

2. Chapter 20: External Causes of Morbidity (V00 – Y99)
Official Guidelines
Medicare Guidelines
Other payor guidelines
AMA ICD10 Book Page 1358

3. General Requirements
Never be sequenced as the first-listed or principal diagnosis.
Intended to provide data for injury research and evaluation of injury prevention strategies.
No National requirement for mandatory ICD-10-CM external cause code reporting.

4. 20.a. General External Cause Coding Guidelines
20.a.1) Used with any code in the range of A00.0 – T88.9 & Z00-Z99
20.a.2) External cause code used for length of treatment
20.a.3) Use the full range of external cause codes
20.a.4) Assign as many external cause codes as necessary
20.a.5) The selection of the appropriate external cause code
20.a.6) External cause code can never be a principal diagnosis
20.a.7) Combination external cause codes
20.a.8) No external cause code needed in certain circumstances

5. 20.b. Place of Occurrence Guidelines
Category Y92, Place of occurrence of the external cause – secondary external cause codes.
Only assigned once, at the initial encounter for treatment.
No 7th character
If place is not stated or not applicable, do not code

6. 20.c. Activity Code
Y93, Activity Code, describes the activity at the time of the injury
Only assigned once, at the initial encounter for treatment.
Not applicable to poisonings, adverse effects, misadventures or sequela.
If activity is not stated or not applicable, do not code
Appropriate for use with external cause and intent codes if provides additional information

7. 20.d. Place of Occurrence, Activity and Status Codes Used with other External Cause Codes.
Sequenced after main external cause code
Generally only one of each per encounter: place of occurrence, activity, external cause status
Rare instances of new injury during hospitalization

8. 20.f. Multiple External Cause Coding Guidelines
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 hierarchy listed below.
Priority Sequencing:
Child and adult abuse
Terrorism
Cataclysmic events
Transport accidents
Activity and external cause status codes assigned after all causal (intent) codes

9. 20.g. Child and Adult Abuse
Abuse, neglect and maltreatment are all classified as assault.
Only code if confirmed abuse
If perpetrator is known, also code from Y07, Perpetrator of maltreatment and neglect.

10. 20.h. Unknown or Undetermined Intent
If the intent of the cause of injury is unknown or unspecified, code as accidental intent.
All transports are assumed accidental intent.
20.h.1) Use of undetermined intent
External cause codes for events of undetermined intent are ONLY for use if the documentation in the record specifies that the intent cannot be determined.

11. 20.i. Sequelae (late Effects)
20.i.1) Sequelae external cause codes
Reported with 7th digit “S” and should be used with any report of a late effect resulting from a previous injury.
20.i.2) Sequela external cause code with a related current injury
Never used with a related current nature of injury code
20.i.3) Use of sequela external cause codes for subsequent visits
Used when a late effect of the initial injury is being treated, not for subsequent visits for follow-up care of the injury when no late effect of the injury has been documented.

12. 20.j. Terrorism Guidelines
20.j.1) Cause of injury identified by the Federal Government (FBI) as terrorism
Code from Y38, Terrorism should be used as the firsts listed external cause code
More than one Y38 code may be assigned if the injury is the result of more than one mechanism of terrorism
20.j.2) Cause of an injury is suspected to be the result of terrorism
Do not code from Y38, suspected is coded as assault
20.j.3) Code Y38.9, Terrorism, secondary effects
Conditions occurring subsequent to the terrorist event.
It is acceptable to code from Y38.9 and another Y38 category if there is an injury due to the initial terrorist event and an injury that is a subsequent result of the terrorist event.

13. 20.k. External Cause Status Code Category Y99
Should be used whenever any other external cause code is assigned for an encounter, except listed exceptions.
Exceptions: poisonings, adverse effects, misadventures or late effects.
Codes are used to indicate the work status at the time of the event.
Ex: military activity, work, student, volunteer, etc.
Do not use if no other external cause codes used
Only used at the initial encounter
If status is not stated or not applicable, do not code