F16.959 maps to CMS-HCC V28 135. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · free HCC coding tools

ICD-10-CM Code View

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Code lookupF16.959

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Mental, Behavioral and Neurodevelopmental disorders (F01-F99) / Mental and behavioral disorders due to psychoactive substance use (F10-F19)

F16.959

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Hallucinogen use, unspecified with hallucinogen-induced psychotic disorder, unspecified

A person uses hallucinogenic drugs and experiences psychotic symptoms caused by the hallucinogen, but the specific type is not detailed.

Buddy Insight

This unspecified psychotic disorder code for hallucinogen use captures psychosis without detailing whether delusions or hallucinations are present.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 135

Drug Use with Psychotic Compl...

Coefficient HCC 135: 0.424 (Community Non-Dual Aged (CNA))

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 081

HHS-HCC 081 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 54

Substance Use with Psychotic ...

Code-level coefficient reference

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

F16.9Hallucinogen use, unspecified F16.95Hallucinogen use, unspecified with hallucinogen-induced psychotic disorder F16.959Hallucinogen use, unspecified with hallucinogen-induced psychotic disorder, unspecified

Inclusion Terms

Official

Other hallucinogen induced psychotic disorder, without use disorder
Phencyclidine induced psychotic disorder, without use disorder

Excludes 2

Official

symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)Inherited from F01-F99

Related Codes

Official

F16.950Hallucinogen use, unspecified with hallucinogen-induced psychotic disorder with delusions F16.951Hallucinogen use, unspecified with hallucinogen-induced psychotic disorder with hallucinations

Includes

Official

disorders of psychological developmentInherited from F01-F99, F16
ecstasyInherited from F01-F99, F16
PCPInherited from F01-F99, F16
phencyclidineInherited from F01-F99, F16

Excludes 1

Official

hallucinogen abuse (F16.1-)Inherited from F16.9
hallucinogen dependence (F16.2-)Inherited from F16.9

Code First

Official

No Code First sequencing instructions are included in this display for F16.959. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for F16.959. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for F16.959. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Documentation of hallucinogen use with psychotic symptoms

Provider query for specific psychotic features

Mental status examination findings supporting psychosis

Differentiation from non-psychotic induced disorders

MEAT Support

HCC Buddy guidance

Documentation of hallucinogen use with psychotic symptoms

Provider query for specific psychotic features

Mental status examination findings supporting psychosis

Differentiation from non-psychotic induced disorders

Audit Caution

HCC Buddy guidance

Using F16.99 instead of F16.959 when psychosis IS present — this loses the higher HCC 54 value

Not querying for specific psychotic features that would allow more precise coding

Confusing this with non-psychotic induced disorders

Missing the opportunity to specify the psychotic features from the mental status exam

Common Mistakes

HCC Buddy guidance

F16.950 — With delusions; preferred when delusions are documented

F16.951 — With hallucinations; preferred when hallucinations are documented

F16.99 — Hallucinogen use, unspecified with unspecified induced disorder; does NOT capture psychosis and maps to lower HCC

F16.259 — Hallucinogen dependence with psychotic disorder, unspecified; more specific regarding dependence

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is F16.959 an HCC code?

Yes. F16.959 (Hallucinogen use, unspecified with hallucinogen-induced psychotic disorder, unspecified) maps to HCC 135, Drug Use with Psychotic Complications under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.424. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: F16.959 is billable and maps to V28 HCC 135, Drug Use with Psychotic Complications. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: F16.959
Description: Hallucinogen use, unspecified with hallucinogen-induced psychotic disorder, unspecified
HCC (V28): HCC 135 — Drug Use with Psychotic Complications
RAF reference coefficient: 0.424
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 135, Drug Use with Psychotic Complications

0.424

ESRDHCC 54, Substance Use with Psychotic Complications

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work F16.959 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for F16.959

For F16.959, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Coder workflow notes

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What This Code Means

F16.959 is the ICD-10-CM diagnosis code for hallucinogen use, unspecified with hallucinogen-induced psychotic disorder, unspecified. A person uses hallucinogenic drugs and experiences psychotic symptoms caused by the hallucinogen, but the specific type is not detailed. F16.959 sits in the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99), within the section covering mental and behavioral disorders due to psychoactive substance use (f10-f19).

Under the CMS-HCC V28 risk adjustment model, F16.959 maps to Drug Use with Psychotic Complications (HCC 135) with a source-labeled community, non-dual, aged reference coefficient of 0.424. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

Use this code when psychotic disorder is present but specific features are not documented. For F16.959, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for F16.959 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use this code when psychotic disorder is present but specific features are not documented
•Query provider to identify whether hallucinations, delusions, or other psychotic features are present

Clinical Significance

This unspecified psychotic disorder code for hallucinogen use captures psychosis without detailing whether delusions or hallucinations are present. Despite the lack of specificity, it still maps to the higher-value psychosis HCC, but should prompt documentation improvement efforts.

Documentation Requirements

✓Documentation of hallucinogen use with psychotic symptoms
✓Provider query for specific psychotic features
✓Mental status examination findings supporting psychosis
✓Differentiation from non-psychotic induced disorders
✓Treatment plan for psychotic symptoms

Commonly Confused Codes

•F16.950: With delusions; preferred when delusions are documented
•F16.951: With hallucinations; preferred when hallucinations are documented
•F16.99: Hallucinogen use, unspecified with unspecified induced disorder; does NOT capture psychosis and maps to lower HCC
•F16.259: Hallucinogen dependence with psychotic disorder, unspecified; more specific regarding dependence