F16.99Hallucinogen use, unspecified with unspecified hallucinogen-induced disorder

F16.99 is the ICD-10-CM diagnosis code for hallucinogen use, unspecified with unspecified hallucinogen-induced disorder. It belongs to category F16 (hallucinogen related disorders), block F10-F19 (mental and behavioral disorders due to psychoactive substance use) and chapter 5 (mental, Behavioral and Neurodevelopmental disorders). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within F16.9, choose F16.99 (with unspecified hallucinogen-induced disorder) only when documentation doesn't support a more specific option: uncomplicated (F16.90), in remission (F16.91), with intoxication (F16.92), with hallucinogen-induced mood disorder (F16.94), with hallucinogen-induced psychotic disorder (F16.95) and with other specified hallucinogen-induced disorder (F16.98).

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 894 (Alcohol, Drug Abuse or Dependence, Left AMA, relative weight 0.6275), DRG 895 (Alcohol, Drug Abuse or Dependence with Rehabilitation Therapy, relative weight 1.4266), DRG 896 (Alcohol, Drug Abuse or Dependence without Rehabilitation Therapy with MCC, relative weight 1.6617) and DRG 897 (Alcohol, Drug Abuse or Dependence without Rehabilitation Therapy without MCC, relative weight 0.8584), in MDC 20 (Alcohol/Drug Use and Alcohol/Drug Induced Organic Mental 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.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 292.9 (unspecified drug-induced mental disorder).