F16.983 maps to CMS-HCC V28 137. 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 lookupF16.983

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)

F16.983

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

Hallucinogen use, unspecified with hallucinogen persisting perception disorder (flashbacks)

This code describes a person who uses hallucinogenic drugs (like LSD or psilocybin) and experiences flashbacks or recurring perceptual disturbances even when not actively using the drug. These flashbacks involve seeing, hearing, or feeling things that aren't really there, happening spontaneously without taking the drug again.

Buddy Insight

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 137

Drug Use Disorder, Moderate/S...

Coefficient HCC 137: 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 082

HHS-HCC 082 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 55

Substance Use Disorder/Modera...

Code-level coefficient reference

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

F16.9Hallucinogen use, unspecified F16.98Hallucinogen use, unspecified with other specified hallucinogen-induced disorder F16.983Hallucinogen use, unspecified with hallucinogen persisting perception disorder (flashbacks)

Inclusion Terms

Official

No inclusion terms are included in this display for F16.983. Check the code and parent instructions in the Code Book.

Excludes 2

Official

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

Related Codes

Official

F16.980Hallucinogen use, unspecified with hallucinogen-induced anxiety disorder F16.988Hallucinogen use, unspecified with other hallucinogen-induced disorder

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 F16.983. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for F16.983. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for F16.983. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Documentation of hallucinogen use history

Description of persisting perceptual disturbances occurring without current drug use

Types of visual or sensory disturbances experienced

Frequency and duration of flashback episodes

MEAT Support

HCC Buddy guidance

Documentation of hallucinogen use history

Description of persisting perceptual disturbances occurring without current drug use

Types of visual or sensory disturbances experienced

Frequency and duration of flashback episodes

Audit Caution

HCC Buddy guidance

Confusing HPPD with active psychosis — HPPD patients typically maintain reality testing

Attributing HPPD symptoms to anxiety or migraine when hallucinogen history is documented

Coding active intoxication when the patient is not currently using hallucinogens

Missing HPPD because the patient presents to ophthalmology or neurology rather than psychiatry

Common Mistakes

HCC Buddy guidance

F16.283 — Hallucinogen dependence with HPPD; preferred when dependence is documented

F16.951 — Hallucinogen use with psychotic disorder with hallucinations; active psychosis vs HPPD flashbacks

F16.920 — Hallucinogen use with intoxication; intoxication is acute, HPPD persists without use

H53.19 — Subjective visual disturbances; does not capture substance etiology

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 F16.983 an HCC code?

Yes. F16.983 (Hallucinogen use, unspecified with hallucinogen persisting perception disorder (flashbacks)) maps to HCC 137, Drug Use Disorder, Moderate/Severe, or Drug Use with Non-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: F16.983 is billable and maps to V28 HCC 137, Drug Use Disorder, Moderate/Severe, or Drug Use with Non-Psychotic Complications. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: F16.983
Description: Hallucinogen use, unspecified with hallucinogen persisting perception disorder (flashbacks)
HCC (V28): HCC 137 — Drug Use Disorder, Moderate/Severe, or Drug Use with Non-Psychotic Complications
RAF reference coefficient: 0.424
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 137, Drug Use Disorder, Moderate/Severe, or Drug Use with Non-Psychotic Complications

0.424

ESRDHCC 55, Substance Use Disorder/Moderate/Severe/Substance Use with 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 F16.983 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for F16.983

For F16.983, 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

F16.983 is the ICD-10-CM diagnosis code for hallucinogen use, unspecified with hallucinogen persisting perception disorder (flashbacks). This code describes a person who uses hallucinogenic drugs (like LSD or psilocybin) and experiences flashbacks or recurring perceptual disturbances even when not actively using the drug. These flashbacks involve seeing, hearing, or feeling things that aren't really there, happening spontaneously without taking the drug again. F16.983 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, F16.983 maps to Drug Use Disorder, Moderate/Severe, or Drug Use with Non-Psychotic Complications (HCC 137) 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.

Verify documentation specifies hallucinogen use with persisting perception disorder (flashbacks) rather than other hallucinogen-related conditions like intoxication or withdrawal. For F16.983, 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 F16.983 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify documentation specifies hallucinogen use with persisting perception disorder (flashbacks) rather than other hallucinogen-related conditions like intoxication or withdrawal
•The '983' code indicates unspecified hallucinogen use; if the specific substance is documented (LSD, psilocybin, etc.), consider using more specific codes in the F16.9- range

Clinical Significance

Hallucinogen persisting perception disorder (HPPD) with unspecified use pattern captures flashback experiences — spontaneous recurrences of hallucinogenic perceptual disturbances occurring without active drug use. HPPD can be chronic and debilitating, with visual disturbances including halos, trails, geometric patterns, and intensified colors.

Documentation Requirements

✓Documentation of hallucinogen use history
✓Description of persisting perceptual disturbances occurring without current drug use
✓Types of visual or sensory disturbances experienced
✓Frequency and duration of flashback episodes
✓Impact on daily functioning and quality of life
✓Differentiation from migraine aura, seizure aura, or primary visual disorders

Commonly Confused Codes

•F16.283: Hallucinogen dependence with HPPD; preferred when dependence is documented
•F16.951: Hallucinogen use with psychotic disorder with hallucinations; active psychosis vs HPPD flashbacks
•F16.920: Hallucinogen use with intoxication; intoxication is acute, HPPD persists without use
•H53.19: Subjective visual disturbances; does not capture substance etiology