ICD-10-CM 2027
ICD-10 code for Hostility
From the official ICD-10-CM alphabetic index entry “Hostility”. Page updated September 29, 2026.
About coding Hostility
The ICD-10-CM code for Hostility is R45.5 (Hostility). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on R45.5.
Within R45 (symptoms and signs involving emotional state), R45.5 is specifically for Hostility. Related codes cover Nervousness (R45.0), Restlessness and agitation (R45.1), unhappiness (R45.2), Demoralization and apathy (R45.3), irritability and anger (R45.4), Violent behavior (R45.6), state of emotional shock and stress, unspecified (R45.7) and other symptoms and signs involving emotional state (R45.8).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 880 (Acute Adjustment Reaction and Psychosocial Dysfunction, relative weight 0.9306), in MDC 19 (Mental Diseases and Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific Hostility codes (official index)
- towards child Z62.3 — Hostility towards and scapegoating of child
Common questions about Hostility ICD-10 codes
What is the ICD-10 code for Hostility?
- R45.5 — Hostility. More specific codes apply when the documentation supports them: Z62.3.
What is the ICD-10 code for towards child hostility?
- Z62.3 — Hostility towards and scapegoating of child.
Is R45.5 billable?
- Yes. R45.5 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can R45.5 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict R45.5 as a principal diagnosis.
Is R45.5 a CC or MCC?
- No. R45.5 is neither a CC nor an MCC under MS-DRG v44.0.