Z86.51 Personal history of combat and operational stress reaction

Billable ICD-10-CM code, FY2026. Exempt from present-on-admission (POA) reporting.

Applies from Z86 Personal history of certain other diseases

Code first

• any follow-up examination after treatment (Z09)

Applies from Z86.5 Personal history of mental and behavioral disorders

Applicable to

• Conditions classifiable to F40-F59

MS-DRG index

Defines the logic of DRG(s) 951 in MDC 23.

Approximate ICD-9-CM (GEMs)

• V11.4 Personal history of combat and operational stress reaction

Medicare Code Edits (MCE v43.1 (April 2026))

• Adult diagnoses (age 15 through 124): Age conflict edit. These diagnoses are clinically expected only in patients age 15 through 124.
• Unacceptable principal diagnosis: These codes describe a circumstance which influences care but is not a current illness or injury, or capture only an underlying condition, and are unacceptable as principal diagnosis.

Code annotations containing back-references to Z86.51

Back-references to Z86

• Use Additional: Z09 Encounter for follow-up examination after completed treatment for conditions other than malignant neoplasm ("code to identify any applicable history of disease code (Z86.-, Z87.-)")

Diagnosis Index entries for Z86.51

• History › personal (of) › combat and operational stress reaction

Nearby codes

• Z86.3 Personal history of endocrine, nutritional and metabolic diseases
• Z86.31 Personal history of diabetic foot ulcer
• Z86.32 Personal history of gestational diabetes
• Z86.39 Personal history of other endocrine, nutritional and metabolic disease
• Z86.5 Personal history of mental and behavioral disorders
• Z86.51 Personal history of combat and operational stress reaction (this code)
• Z86.59 Personal history of other mental and behavioral disorders
• Z86.6 Personal history of diseases of the nervous system and sense organs
• Z86.61 Personal history of infections of the central nervous system
• Z86.69 Personal history of other diseases of the nervous system and sense organs
• Z86.7 Personal history of diseases of the circulatory system