Alphabetic Index FY2027

F16.9

Hallucinogen use, unspecified

FY2027Chapter 5: Mental, Behavioral and Neurodevelopmental disorders/F10–F19 Mental and behavioral disorders due to psychoactive substance use

Non-billable headerNot valid on its own. Use one of the more specific codes under it.

F16.9 is a non-billable ICD-10-CM code header for hallucinogen use, unspecified. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are F16.90 Hallucinogen use, unspecified, uncomplicated; F16.91 Hallucinogen use, unspecified, in remission; F16.92 Hallucinogen use, unspecified with intoxication; F16.94 Hallucinogen use, unspecified with hallucinogen-induced mood disorder and 3 more. Its coding notes include 2 Excludes1 entries and 1 Excludes2 entry.

Guidelines tips

From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.

When use, abuse and dependence of the same substance are all documented, one code is assigned, by a set hierarchy.

Guidelines I.C.5.b.2Substance use, abuse and dependence: only one codeRead the official text

A medical condition due to substance use is coded from the Alphabetic Index along with the substance use, abuse or dependence code, not as a substance-induced disorder.

Guidelines I.C.5.b.4Medical conditions due to substance useRead the official text

Excludes1

Not coded here. The listed conditions generally should not be reported together.

This code

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Also from chapter/block level (1 note)
Inherited from Chapter 5 Mental, Behavioral and Neurodevelopmental disorders
  • symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)

Includes

Further defines or gives examples of the content of the category.

Inherited from F16 Hallucinogen related disorders
  • ecstasy
  • PCP
  • phencyclidine
Also from chapter/block level (1 note)
Inherited from Chapter 5 Mental, Behavioral and Neurodevelopmental disorders
  • disorders of psychological development

More specific codes under F16.9 7