ICD-10-CM 2027
ICD-10 code for Untruthfulness
From the official ICD-10-CM alphabetic index entry “Untruthfulness, child problem”. Page updated September 29, 2026.
About coding Untruthfulness
The ICD-10-CM code for Untruthfulness is F91.8 (Other conduct disorders).
Within F91, choose F91.8 (Other conduct disorders) only when documentation doesn't support a more specific option: conduct disorder confined to family context (F91.0), conduct disorder, childhood-onset type (F91.1), conduct disorder, adolescent-onset type (F91.2), Oppositional defiant disorder (F91.3) and conduct disorder, unspecified (F91.9).
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 886 (Behavioral and Developmental Disorders, relative weight 1.8678), 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.
Common questions about Untruthfulness ICD-10 codes
What is the ICD-10 code for Untruthfulness?
- F91.8 — Other conduct disorders.
Is F91.8 billable?
- Yes. F91.8 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can F91.8 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict F91.8 as a principal diagnosis.
Is F91.8 a CC or MCC?
- No. F91.8 is neither a CC nor an MCC under MS-DRG v44.0.