F16.983
BillableHallucinogen use, unspecified with hallucinogen persisting perception disorder (flashbacks)
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is F16.983 an HCC code?
Yes. F16.983 maps to Drug Use Disorder/Substance Use Disorder, Moderate/Severe under the CMS-HCC V28 risk adjustment model (and Drug/Alcohol Dependence under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for F16.983
For F16.983 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- 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
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed F16.983 during that encounter — not just copy-forwarded from a problem list.
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/Substance Use Disorder, Moderate/Severe (HCC 137) with a community, non-dual, aged base RAF weight of 0.358. Under the older CMS-HCC V24 model, F16.983 maps to Drug/Alcohol Dependence (HCC 55) with a community, non-dual, aged base RAF weight of 0.334. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Verify documentation specifies hallucinogen use with persisting perception disorder (flashbacks) rather than other hallucinogen-related conditions like intoxication or withdrawal. Because F16.983 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. 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, RAF weights, 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