F18.17 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 · HCC coding software

ICD-10-CM Code View

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Code lookupF18.17

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)

F18.17

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

Inhalant abuse with inhalant-induced dementia

A person is abusing inhalants and has developed dementia (progressive loss of memory and cognitive function) caused by the inhalant use.

Buddy Insight

Inhalant abuse with induced dementia represents one of the most devastating complications of inhalant use.

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

Inclusion Terms

Official

Inhalant use disorder, mild, with inhalant induced major neurocognitive disorder

Excludes 2

Official

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

Related Codes

Official

F18.10Inhalant abuse, uncomplicated F18.11Inhalant abuse, in remission F18.12Inhalant abuse with intoxication F18.14Inhalant abuse with inhalant-induced mood disorder F18.15Inhalant abuse with inhalant-induced psychotic disorder

Includes

Official

disorders of psychological developmentInherited from F01-F99, F18
volatile solventsInherited from F01-F99, F18

Excludes 1

Official

inhalant dependence (F18.2-)Inherited from F18.1
inhalant use, unspecified (F18.9-)Inherited from F18.1

Code First

Official

No Code First sequencing instructions are included in this display for F18.17. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for F18.17. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for F18.17. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Documentation of inhalant abuse (current or chronic history)

Cognitive assessment demonstrating dementia (Mini-Mental State Examination, Montreal Cognitive Assessment, or neuropsychological testing)

Provider statement that dementia is caused by inhalant use

Brain imaging showing white matter changes, cerebellar atrophy, or cortical atrophy

MEAT Support

HCC Buddy guidance

Documentation of inhalant abuse (current or chronic history)

Cognitive assessment demonstrating dementia (Mini-Mental State Examination, Montreal Cognitive Assessment, or neuropsychological testing)

Provider statement that dementia is caused by inhalant use

Brain imaging showing white matter changes, cerebellar atrophy, or cortical atrophy

Audit Caution

HCC Buddy guidance

Not linking the dementia diagnosis to inhalant use, coding it as primary dementia

Missing the dementia diagnosis because the patient is young — inhalant dementia affects younger patients

Confusing acute intoxication effects with chronic dementia — dementia persists after cessation

Not documenting neurocognitive testing results that support the dementia diagnosis

Common Mistakes

HCC Buddy guidance

F18.27 — Inhalant dependence with induced dementia; use when dependence is documented

F18.97 — Inhalant use, unspecified with induced dementia; less specific use pattern

F03.90 — Unspecified dementia without behavioral disturbance; use for dementia of unknown etiology

G31.2 — Degeneration of nervous system due to alcohol; different substance category

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 F18.17 an HCC code?

Yes. F18.17 (Inhalant abuse with inhalant-induced dementia) 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: F18.17 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: F18.17
Description: Inhalant abuse with inhalant-induced dementia
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 F18.17 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for F18.17

For F18.17, 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

F18.17 is the ICD-10-CM diagnosis code for inhalant abuse with inhalant-induced dementia. A person is abusing inhalants and has developed dementia (progressive loss of memory and cognitive function) caused by the inhalant use. F18.17 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, F18.17 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.

Document that the dementia is directly caused by chronic inhalant abuse, not from another etiology. For F18.17, 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 F18.17 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Document that the dementia is directly caused by chronic inhalant abuse, not from another etiology
•This represents long-term neurotoxic effects of inhalant abuse and may be irreversible

Clinical Significance

Inhalant abuse with induced dementia represents one of the most devastating complications of inhalant use. Chronic exposure to volatile solvents (especially toluene) causes progressive white matter destruction, cerebellar degeneration, and cognitive decline that may be irreversible. This is a life-altering diagnosis carrying significant care complexity.

Documentation Requirements

✓Documentation of inhalant abuse (current or chronic history)
✓Cognitive assessment demonstrating dementia (Mini-Mental State Examination, Montreal Cognitive Assessment, or neuropsychological testing)
✓Provider statement that dementia is caused by inhalant use
✓Brain imaging showing white matter changes, cerebellar atrophy, or cortical atrophy
✓Timeline of cognitive decline relative to inhalant exposure
✓Assessment of functional status and need for supervision/care
✓Differentiation from other dementia etiologies

Commonly Confused Codes

•F18.27: Inhalant dependence with induced dementia; use when dependence is documented
•F18.97: Inhalant use, unspecified with induced dementia; less specific use pattern
•F03.90: Unspecified dementia without behavioral disturbance; use for dementia of unknown etiology
•G31.2: Degeneration of nervous system due to alcohol; different substance category