Injury and Certain Other Consequences of External Causes and External Causes of Morbidity
(ICD-10-CM Chapter 19, Codes S00-T88 and Chapter 20, Codes V00-Y99)
Learning Objectives
2. Identify the various types of injuries
3. Assign the correct Z codes, External cause codes, and procedure codes related to injuries
4. Identify common treatments, medications, and diagnostic tests
5. Explain the importance of documentation in relation to MS-DRGs for reimbursement
Abbreviations/Acronyms
FB foreign body
ICD-9-CM International Classification of Diseases, 9th Revision, Clinical Modification
ICD-10-CM International Classification of Diseases, 10th Revision, Clinical Modification
ICD-10-PCS International Classification of Diseases, 10th Revision, Procedure Coding System
MRI magnetic resonance imaging
MS-DRG Medicare Severity diagnosis-related group
OIG Office of the Inspector General
ORIF open reduction with internal fixation
SLAP superior labrum anterior-posterior
ICD-10-CM Official Guidelines for Coding and Reporting
Please refer to the companion Evolve website for the most current guidelines.
19. Chapter 19: Injury, poisoning, and certain other consequences of external causes (S00-T88)
a. Application of 7th Characters in Chapter 19
Most categories in chapter 19 have a 7th character requirement for each applicable code. Most categories in this chapter have three 7th character values (with the exception of fractures): A, initial encounter, D, subsequent encounter and S, sequela. Categories for traumatic fractures have additional 7th character values.
7th character “A”, initial encounter is used while the patient is receiving active treatment for the condition. Examples of active treatment are: surgical treatment, emergency department encounter, and evaluation and treatment by a new physician.
7th character “D” subsequent encounter is used for encounters after the patient has received active treatment of the condition and is receiving routine care for the condition during the healing or recovery phase. Examples of subsequent care are: cast change or removal, removal of external or internal fixation device, medication adjustment, other aftercare and follow up visits following treatment of the injury or condition.
The aftercare Z codes should not be used for aftercare for conditions such as injuries or poisonings, where 7th characters are provided to identify subsequent care. For example, for aftercare of an injury, assign the acute injury code with the 7th character “D” (subsequent encounter).
7th character “S”, sequela, is for use for complications or conditions that arise as a direct result of a condition, such as scar formation after a bum. The scars are sequelae of the bum. When using 7th character “S”, it is necessary to use both the injury code that precipitated the sequela and the code for the sequela itself. The “S” is added only to the injury code, not the sequela code. The 7th character “S” identifies the injury responsible for the sequela. The specific type of sequela (e.g. scar) is sequenced first, followed by the injury code.
b. Coding of Injuries
When coding injuries, assign separate codes for each injury unless a combination code is provided, in which case the combination code is assigned. Code T07, Unspecified multiple injuries should not be assigned in the inpatient setting unless information for a more specific code is not available. Traumatic injury codes (S00-TI4.9) are not to be used for normal, healing surgical wounds or to identify complications of surgical wounds.
The code for the most serious injury, as determined by the provider and the focus of treatment, is sequenced first.
1) Superficial injuries
Superficial injuries such as abrasions or contusions are not coded when associated with more severe injuries of the same site.
2) Primary injury with damage to nerves/blood vessels
When a primary injury results in minor damage to peripheral nerves or blood vessels, the primary injury is sequenced first with additional code(s) for injuries to nerves and spinal cord (such as category S04), and/or injury to blood vessels (such as category S15). When the primary injury is to the blood vessels or nerves, that injury should be sequenced first.
c. Coding of Traumatic Fractures
The principles of multiple coding of injuries should be followed in coding fractures. Fractures of specified sites are coded individually by site in accordance with both the provisions within categories S02, S12, S22, S32, S42, S49, S52, S59, S62, S72, S79, S82, S89, S92 and the level of detail furnished by medical record content.
A fracture not indicated as open or closed should be coded to closed. A fracture not indicated whether displaced or not displaced should be coded to displaced.
More specific guidelines are as follows:
1) Initial vs. Subsequent Encounter for Fractures
Traumatic fractures are coded using the appropriate 7th character extension for initial encounter (A, B, C) while the patient is receiving active treatment for the fracture. Examples of active treatment are: surgical treatment, emergency department encounter, and evaluation and treatment by a new physician. The appropriate 7th character for initial encounter should also be assigned for a patient who delayed seeking treatment for the fracture or nonunion.
Fractures are coded using the appropriate 7th character extension for subsequent care for encounters after the patient has completed active treatment of the fracture and is receiving routine care for the fracture during the healing or recovery phase. Examples of fracture aftercare are: cast change or removal, removal of external or internal fixation device, medication adjustment, and follow-up visits following fracture treatment.
Care for complications of surgical treatment for fracture repairs during the healing or recovery phase should be coded with the appropriate complication codes.
Care of complications of fractures, such as malunion and nonunion, should be reported with the appropriate 7th character extensions for subsequent care with nonunion (K, M, N,) or subsequent care with malunion (P, Q, R).
A code from category M80, not a traumatic fracture code, should be used for any patient with known osteoporosis who suffers a fracture, even if the patient had a minor fall or trauma, if that fall or trauma would not usually break a normal, healthy bone.
See Section I.C.13. Osteoporosis.
The aftercare Z codes should not be used for aftercare for traumatic fractures. For aftercare of a traumatic fracture, assign the acute fracture code with the appropriate 7th character.
2) Multiple fractures sequencing
Multiple fractures are sequenced in accordance with the severity of the fracture.
As with Z codes, detailed guidelines have been put forth for the use of external cause codes. The Alphabetic Index for these codes is located prior to the Tabular List and after the Table of Neoplasms and Table of Drugs and Chemicals. Codes are located by using the Alphabetic Index and then verifying the appropriate code in the Tabular List. The assignment of external cause codes may depend on facility policy, particular state requirements, and the following guidelines. For example, the assignment of external cause codes may be useful in determining the number of head injuries that occur as a result of bicycle accidents. This data may be used to support bicycle helmet programs in a particular city or state. Codes for external causes are never used as a principal or first-listed diagnosis. External cause codes are always assigned as an additional code(s). External cause codes are used to identify the cause, the intent, the place of occurrence, the activity, and the status at the time of the event.
The External cause guidelines are used for injuries, poisonings, adverse effects, and complications of surgical and medical care, which are covered in the next three chapters. Some of the external cause guidelines may be addressed in subsequent chapters so the numbering/lettering may not be sequential.
20. Chapter 20: External Causes of Morbidity (V01-Y99)
Introduction: These guidelines are provided for the reporting of external causes of morbidity codes in order that there will be standardization in the process. These codes are secondary codes for use in any health care setting.
External cause codes are intended to provide data for injury research and evaluation of injury prevention strategies. These codes capture how the injury or health condition happened (cause), the intent (unintentional or accidental; or intentional, such as suicide or assault), the place where the event occurred the activity of the patient at the time of the event, and the person’s status (e.g., civilian, military).
a. General External Cause Coding Guidelines
1) Used with any code in the range of A00.0-T88.9, Z00-Z99
An external cause code may be used with any code in the range of A00.0-T88.9, Z00-Z99, classification that is a health condition due to an external cause. Though they are most applicable to injuries, they are also valid for use with such things as infections or diseases due to an external source, and other health conditions, such as a heart attack that occurs during strenuous physical activity.
2) External cause code used for length of treatment
Assign the external cause code, with the appropriate 7th character (initial encounter, subsequent encounter or sequela) for each encounter for which the injury or condition is being treated.
3) Use the full range of external cause codes
Use the full range of external cause codes to completely describe the cause, the intent, the place of occurrence, and if applicable, the activity of the patient at the time of the event, and the patient’s status, for all injuries, and other health conditions due to an external cause.
4) Assign as many external cause codes as necessary
Assign as many external cause codes as necessary to fully explain each cause. If only one external code can be recorded, assign the code most related to the principal diagnosis.
5) The selection of the appropriate external cause code
The selection of the appropriate external cause code is guided by the Alphabetic Index of External Causes and by Inclusion and Exclusion notes in the Tabular List.
6) External cause code can never be a principal diagnosis
An external cause code can never be a principal (first-listed) diagnosis.
7) Combination external cause codes
Certain of the external cause codes are combination codes that identify sequential events that result in an injury, such as a fall which results in striking against an object. The injury may be due to either event or both. The combination external cause code used should correspond to the sequence of events regardless of which caused the most serious injury.
8) No external cause code needed in certain circumstances
No external cause code from Chapter 20 is needed if the external cause and intent are included in a code from another chapter (e.g. T36.0x1- Poisoning by penicillins, accidental (unintentional)).
b. Place of Occurrence Guideline
Codes from category Y92, Place of occurrence of the external cause, are secondary codes for use after other external cause codes to identify the location of the patient at the time of injury or other condition.
A place of occurrence code is used only once, at the initial encounter for treatment. No 7th characters are used for Y92. Only one code from Y92 should be recorded on a medical record. A place of occurrence code should be used in conjunction with an activity code, Y93.
Do not use place of occurrence code Y92.9 if the place is not stated or is not applicable.
c. Activity Code
Assign a code from category Y93, Activity code, 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 Y93 should be recorded on a medical record. An activity code should be used in conjunction with a place of occurrence code, Y92.
If a patient is a student but is injured while performing an activity for income, use 7th character “2”, work related activity. A work related activity is any activity for which payment or income is received.
The activity codes are not applicable to poisonings, adverse effects, misadventures or sequela.
Do not assign Y93.9, Unspecified activity, if the activity is not stated.
A code from category Y93 is appropriate for use with external cause and intent codes if identifying the activity provides additional information about the event.
d. Place of Occurrence, Activity, and Status Codes Used with other External Cause Code
When applicable, place of occurrence, activity, and external cause status codes are sequenced after the main external cause code(s). Regardless of the number of external cause codes assigned, there should be only one place of occurrence code, one activity code, and one external cause status code assigned to an encounter.
e. If the Reporting Format Limits the Number of External Cause Codes
If the reporting format limits the number of external cause codes that can be used in reporting clinical data, report the code for the cause/intent most related to the principal diagnosis. If the format permits capture of additional external cause codes, the cause/intent, including medical misadventures, of the additional events should be reported rather than the codes for place, activity, or external status.
f. Multiple External Cause Coding Guidelines
More than one external cause code is required to fully describe the external cause of an illness or injury. The assignment of external cause codes should be sequenced in the following priority:
If two or more events cause separate injuries, an external cause code should be assigned for each cause. The first-listed external cause code will be selected in the following order:
External codes for child and adult abuse take priority over all other external cause codes.
See Section I.C.19., Child and Adult abuse guidelines.
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 cataclysmic events, child and adult abuse and terrorism.
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.
h. Unknown or Undetermined Intent Guideline
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. All transport accident categories assume accidental intent.
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.
i. Sequelae (Late Effects) of External Cause Guidelines
1) Sequelae external cause codes
Sequela are reported using the external cause code with the 7th character “S” for sequela. These codes should be used with any report of a late effect or sequela resulting from a previous injury.
2) Sequela external cause code with a related current injury
A sequela external cause code should never be used with a related current nature of injury code.
3) Use of sequela external cause codes for subsequent visits
Use a late effect 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, to receive rehabilitative therapy) of the injury when no late effect of the injury has been documented.
1) Cause of injury identified by the Federal Government (FBI) as terrorism
When the cause of an injury is identified by the Federal Government (FBI) as terrorism, the first-listed external cause code should be a code from category Y38, Terrorism. The definition of terrorism employed by the FBI is found at the inclusion note at the beginning of category Y38. Use additional code for place of occurrence (Y92.-). More than one Y38 code may be assigned if the injury is the result of more than one mechanism of terrorism.
2) Cause of an injury is suspected to be the result of terrorism
When the cause of an injury is suspected to be the result of terrorism a code from category Y38 should not be assigned. Suspected cases should be classified as assault.
3) Code Y38.9, Terrorism, secondary effects
Assign code Y38.9, Terrorism, secondary effects, for conditions occurring subsequent to the terrorist event. This code should not be assigned for conditions that are due to the initial terrorist act.
It is acceptable to assign code Y38.9 with another code from Y38 if there is an injury due to the initial terrorist event and an injury that is a subsequent result of the terrorist event.
k. External cause status
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. Assign a code from category Y99, External cause status, to indicate the work status of the person at the time the event occurred. The status code indicates whether the event occurred during military activity, whether a non-military person was at work, whether an individual including a student or volunteer was involved in a non-work activity at the time of the causal event.
A code from Y99, External cause status, should be assigned, when applicable, with other external cause codes, such as transport accidents and falls. The external cause status codes are not applicable to poisonings, adverse effects, misadventures or late effects.
Do not assign a code from category Y99 if no other external cause codes (cause, activity) are applicable for the encounter.
An external cause status code is used only once, at the initial encounter for treatment. Only one code from Y99 should be recorded on a medical record.
Do not assign code Y99.9, Unspecified external cause status, if the status is not stated.
Apply the General Coding Guidelines as found in Chapter 5 and the Procedural Coding Guidelines as found in Chapters 6 and 7.
Remember that External cause codes identify how an injury occurred and the intent. External cause codes also identify the place that an injury occurred and describe the activity that caused the injury or other health condition. At the beginning of Chapter 19 in the ICD-10-CM code book, special instructions state that codes from this chapter should be used as secondary codes and that a code from another chapter of the Classification should be assigned indicating the nature of the injury or health condition (Figure 23-1). Also remember, do NOT use code Y92.9 if the place of occurrence is not stated or Y93.9 if the activity was not stated. Physician documentation may not include the detail required to assign the place of occurrence, activity, and the patient’s status at the time of the event.
Exercise 23-1
Assign only the External cause codes to the following. Remember that External cause codes provide information about the cause and intent of an injury. If the place of occurrence, the status of the patient at the time, and/or an activity code is applicable, assign the appropriate codes. Assume initial episode of care, unless otherwise specified.
| 1. Patient is employed doing data entry and has carpal tunnel syndrome from using computer keyboard | ___________________ |
| 2. Patient fell from a ladder while working as an employee at church | ___________________ |
| 3. Patient was bitten by a dog while jogging at the public park | ___________________ |
| 4. Patient was injured in a motorcycle accident. Patient was the driver and lost control due to wet interstate highway | |
| ___________________ | |
| 5. Patient accidentally lacerated hand with hunting knife while hunting in the woods | ___________________ |
| 6. Patient fell out of bed at the nursing home and was injured | ___________________ |
| 7. Patient was injured during an assault with a baseball bat in public parking garage | ___________________ |
| 8. Patient was injured while playing in NHL hockey game. Patient was checked into the boards by another player and fell to the ice | ___________________ |
| 9. Patient was the victim of accidental drowning in lake | ___________________ |
| 10. Patient was the driver and was injured during a motor vehicle collision with a train | ___________________ |
Anatomy and Physiology
The musculoskeletal chapter outlines the anatomy and physiology that is pertinent to injury. Internal organs and the blood vessels may also be involved in an injury. These are outlined in their respective body system chapters.
Disease Conditions
Injury, Poisoning, and Certain Other Consequences of External Causes (S00-T88), Chapter 19 in the ICD-10-CM code book, covers a wide range of codes that will be discussed in the next three chapters of this textbook. Categories marked with an asterisk (*) are covered in this chapter. Chapter 24 discusses burns, adverse effects, and poisonings and Chapter 25 is dedicated to complications associated with surgical and medical care.
Chapter 19 in the ICD-10-CM code book—Injury, Poisoning, and Certain Other Consequences of External Causes (S00-T88)—is divided into the following categories:
| SECTION | SECTION TITLES |
| *S00-S09 | Injuries to the head |
| *S10-S19 | Injuries to the neck |
| *S20-S29 | Injuries to the thorax |
| *S30-S39 | Injuries to the abdomen, lower back, lumbar spine, pelvis, and external genitalia |
| *S40-S49 | Injuries to the shoulder and upper arm |
| *S50-S59 | Injuries to the elbow and forearm |
| *S60-S69 | Injuries to the wrist and hand |
| *S70-S79 | Injuries to the hip and thigh |
| *S80-S89 | Injuries to the knee and lower leg |
| *S90-S99 | Injuries to the ankle and foot |
| *T07 | Injuries involving multiple body regions |
| *T14 | Injury of unspecified body region |
| *T15-T19 | Effects of foreign body entering through natural orifice |
| T20-T32 | Burns and corrosions |
| T33-T34 | Frostbite |
| T36-T50 | Poisoning by, adverse effect of, and underdosing of drugs, medicaments, and biological substances |
| T51-T65 | Toxic effects of substances chiefly nonmedicinal as to source |
| T66-T78 | Other and unspecified effects of external causes |
| *T79 | Certain early complications of trauma |
| T80-T88 | Complications of surgical and medical care, not elsewhere classified |
Chapter 20 is divided into the following categories:
| 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 motor vehicle injured in transport accident |
| V40-V49 | Car occupant injured in 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-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-Y09 | Assault |
| Y21-Y33 | Event of undetermined intent |
| Y35-Y38 | Legal intervention, operations of war, military operations, and terrorism |
| 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 |
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