Dementia — Clinical Documentation Guide (2026)

🔍 Definition

Dementia is a clinical syndrome characterized by acquired, progressive deterioration in cognitive function — including memory, language, problem-solving, executive function, and behavior — severe enough to interfere with daily activities and social or occupational functioning. It is not a single disease but a clinical phenotype caused by multiple underlying pathological processes. Per CMS ICD-10-CM FY2026 guidelines, dementia is coded using a structured hierarchy that combines etiology, severity, and behavioral disturbance into a single highly specific code combination.

The major subtypes encountered in clinical coding include: Alzheimer’s disease dementia (most common, ~60–70% of cases), vascular dementia (~15–20%), dementia with Lewy bodies (~5–10%), frontotemporal dementia (FTD/Pick’s disease) (~5–10%), and dementia due to other medical conditions (Parkinson’s disease, Huntington’s disease, HIV, TBI, Creutzfeldt-Jakob disease, and others). Accurate documentation and coding of the underlying etiology, severity level, and any behavioral or neuropsychiatric disturbances are essential for CMS-HCC v28 risk adjustment and for capturing the correct HCC category (HCC 124 vs. HCC 125).

🗂️ Alternative Terminology

The following table identifies formal clinical and lay terminology used in documentation for dementia spectrum conditions. Coders must recognize all variants to ensure accurate code assignment.

🩺 Signs & Symptoms

Clinical documentation should capture both cognitive and neuropsychiatric/behavioral features, as the latter directly affect ICD-10-CM code selection and HCC assignment.

Cognitive Symptoms

• Memory impairment: Episodic memory loss (recent > remote), difficulty learning new information, forgetting appointments, names, or recent events
• Language dysfunction: Word-finding difficulty, aphasia, reduced vocabulary, circumlocution
• Executive dysfunction: Impaired planning, sequencing, abstract reasoning, judgment
• Visuospatial impairment: Getting lost in familiar environments, difficulty with spatial tasks (Alzheimer’s, DLB)
• Attention/concentration deficits: Especially prominent in vascular and Lewy body dementia

Behavioral and Neuropsychiatric Symptoms (BPSD) — Code Triggers

• Agitation/aggression: Verbal or physical agitation, combativeness, resistiveness to care → 6th character “1” or “11”
• Psychotic disturbance: Visual/auditory hallucinations, paranoid delusions, misidentification syndromes → 6th character “2”
• Mood disturbance: Depression, emotional lability, apathy, dysphoria → 6th character “3”
• Anxiety disturbance: Generalized anxiety, sundowning, restlessness → 6th character “4”
• Sleep disturbance: REM sleep behavior disorder (especially DLB), insomnia, hypersomnia
• Wandering: Elopement behavior, getting lost

Neurological Signs by Subtype

• Alzheimer’s: Gradual onset, symmetric cortical atrophy; anosmia, myoclonus (late)
• Vascular: Stepwise decline, focal neurological deficits, history of stroke/TIA/hypertension
• Lewy body: Fluctuating cognition, visual hallucinations, parkinsonism, REM sleep behavior disorder (core features)
• FTD/Pick’s: Personality change, disinhibition, hyperorality, semantic/syntactic language loss
• Parkinson’s dementia: Motor features precede cognitive decline by ≥1 year

🧭 Differential Diagnosis

Coders and CDI specialists must be alert to conditions that may mimic or co-exist with dementia, as each has distinct code assignments and clinical implications.

📋 Clinical Indicators for Coders/CDI

The following table summarizes key documentation elements that support specific dementia code assignments. CDI specialists should audit for these indicators in every dementia encounter.

🦴 Anatomy & Pathophysiology

Understanding the pathophysiological basis of dementia subtypes helps coders and CDI specialists identify documentation clues that support specific code selection.

Alzheimer’s Disease

Alzheimer’s disease (AD) is characterized by extracellular amyloid-beta (Aβ) plaques and intraneuronal neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau protein. Neurodegeneration begins in the entorhinal cortex and hippocampus (explaining early episodic memory loss) before spreading to association cortices. Per National Institute on Aging (NIA), AD affects approximately 6.7 million Americans age 65 and older. The 2023 FDA approvals of lecanemab (Leqembi) and 2024 approval of donanemab (Kisunla) — both anti-amyloid monoclonal antibodies — represent the first disease-modifying therapies for early AD, targeting Aβ clearance.

Vascular Dementia

Vascular cognitive impairment arises from cerebrovascular disease — including large-vessel strokes, small-vessel (lacunar) disease, and white matter hyperintensities. The mechanism involves ischemic injury to cortical and subcortical networks essential for cognition, particularly frontal-subcortical circuits. Risk factors (hypertension, diabetes, atrial fibrillation, dyslipidemia) are the same as for stroke. Unlike Alzheimer’s, vascular dementia often presents with stepwise decline rather than gradual progression.

Lewy Body Dementia

Dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD) share the pathological substrate of alpha-synuclein aggregates (Lewy bodies) distributed in cortical and limbic regions. DLB is distinguished by dementia onset concurrent with or preceding motor features; in PDD, motor symptoms precede cognitive decline by ≥1 year. The characteristic fluctuating cognition and visual hallucinations result from cholinergic deficits and limbic involvement. REM sleep behavior disorder (RBD) is an early biomarker. ICD-10-CM uses G31.83 for Lewy body disease, coded with F02.8x for the dementia manifestation.

Frontotemporal Dementia (FTD / Pick’s Disease)

FTD encompasses a heterogeneous group of neurodegenerative disorders with selective frontal and temporal lobe atrophy. Pathologically, FTD is associated with tau (Pick bodies in Pick’s disease; MAPT mutations), TDP-43, or FUS protein inclusions. The behavioral variant (bvFTD) presents with personality change, disinhibition, and executive dysfunction; language variants present as progressive aphasia. G31.01 (Pick’s disease) and G31.09 (other FTD) are coded with F02.8x for the dementia manifestation.

Severity Staging Correlates

The FY2026 severity subcategories (A=mild, B=moderate, C=severe) align with validated staging tools: the Alzheimer’s Association staging, CDR (Clinical Dementia Rating scale), and FAST (Functional Assessment Staging Test). CDR 0.5–1 corresponds to mild; CDR 2 to moderate; CDR 3 to severe. Documentation of specific CDR, MMSE, or MoCA scores supports severity axis assignment and defends against retrospective audit challenges.

💊 Medication Impact / Treatment

Pharmacological and non-pharmacological management of dementia directly informs code selection, CDI queries, and HCPCS/CPT billing opportunities.

Cholinesterase Inhibitors (AChEIs)

First-line symptomatic therapy for mild-to-moderate Alzheimer’s dementia includes donepezil (Aricept — all stages), rivastigmine (Exelon — also for PDD), and galantamine (Razadyne). These agents inhibit acetylcholinesterase, increasing synaptic acetylcholine. All are oral medications billed under Part D via NDC; rivastigmine transdermal patch (HCPCS J3490) may be billed under Part B in select circumstances. Presence of AChEI prescriptions in the medication list is a strong CDI indicator that the clinician has diagnosed and is treating dementia.

NMDA Receptor Antagonist

Memantine (Namenda) is approved for moderate-to-severe Alzheimer’s dementia; it may be combined with an AChEI. Memantine is also used off-label in other dementia subtypes. Documentation of memantine use supports severity coding (moderate/severe subcategory — B or C).

Disease-Modifying Anti-Amyloid Therapies (Early AD)

• Lecanemab (Leqembi) — FDA-approved January 2023 (accelerated) and July 2023 (full approval) for early AD (MCI due to AD or mild AD dementia with confirmed amyloid pathology). HCPCS J0173 (lecanemab-irmb) — note: code may be pending; J3490 (unclassified biologic) used when specific J-code not yet assigned. Billed IV infusion. Per FDA approvals database, full approval granted July 2023.
• Donanemab (Kisunla) — FDA-approved July 2024 for early symptomatic AD. HCPCS J3490 or assigned J-code when available. IV infusion; requires amyloid PET or CSF confirmation.

Behavioral/Neuropsychiatric Symptom Management

• Antipsychotics (quetiapine, risperidone, olanzapine — all off-label): for agitation, psychosis; FDA black box warning for use in elderly with dementia (increased mortality risk)
• Antidepressants (SSRIs — sertraline, citalopram; SNRIs): for mood disturbance, anxiety, apathy
• Benzodiazepines (short-term only): for acute agitation; risk of falls, paradoxical agitation
• Melatonin / trazodone: for sleep-wake cycle disturbances
• Pimavanserin (Nuplazid): FDA-approved for Parkinson’s disease psychosis; investigational for dementia-related psychosis (DRP)

Non-Pharmacological Interventions

Cognitive stimulation therapy, structured activity programs, caregiver training, and environmental modifications are mainstays of dementia care. Music therapy, reminiscence therapy, and sensory stimulation are evidence-based non-drug approaches for BPSD management per Alzheimer’s Association treatment guidelines.

Preview ends here. The full guide continues with FY2026 ICD-10-CM code sets, CPT surgical coding, MS-DRG mapping, reimbursement guidance, CDI query templates, and an audit checklist — all available to CCO Members.

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📘 ICD-10-CM Guidelines (FY2026)

Etiology/Manifestation Convention — Critical Sequencing Rules

The ICD-10-CM Official Guidelines for Coding and Reporting FY2026 (Section I.C.5.a and Tabular instructions) mandate the following sequencing rules for dementia:

1. Alzheimer’s disease with dementia: Assign G30.x (Alzheimer’s disease) as the principal/first-listed diagnosis, followed by F02.8x (dementia in Alzheimer’s) as an additional code. The Tabular note at G30 states “Use additional code to identify: dementia with behavioral disturbance (F02.8x).” The note at F02.8x states “Code first the underlying physiological condition.” This is the etiology/manifestation convention — do NOT reverse the order.
2. Vascular dementia (F01.5x): F01.5x codes are combination codes that include both the vascular etiology and the dementia. No separate cerebrovascular disease code is required unless a distinct acute stroke or other condition is present. F01.5x is sequenced as appropriate based on the reason for the encounter.
3. Lewy body disease (G31.83): Code G31.83 first (Lewy body dementia / dementia with Lewy bodies), then F02.8x as an additional code. Per Tabular note at G31.83: “Use additional code for associated symptoms” including dementia.
4. Parkinson’s disease with dementia: Code G20 (Parkinson’s disease) first, followed by F02.8x for the dementia manifestation. Do NOT assume dementia is present in every Parkinson’s patient — it must be explicitly documented.
5. FTD/Pick’s disease: Code G31.01 (Pick’s disease) or G31.09 (other FTD) first, then F02.8x as an additional code.
6. Dementia without identified etiology: Use F03.9x (unspecified dementia) when no underlying cause is documented. CDI should query for etiology before defaulting to F03.9x.
7. Huntington’s disease: Code G10 (Huntington’s disease) first, then F02.8x.
8. CJD with dementia: Code prion disease (A81.0x) first, then F02.8x.
9. HIV with dementia: B20 (HIV disease) first, then F02.8x.

Severity and Behavioral Disturbance Axis (FY2023+ — Operative FY2026)

Effective FY2023, dementia codes include a severity axis and expanded behavioral disturbance 6th character. This structure applies to F01.5x, F02.8x, and F03.9x code families:

• 5th character (severity): 9 = unspecified severity; A = mild; B = moderate; C = severe
• 6th character (behavioral/neuropsychiatric disturbance):
  • 0 = without behavioral disturbance, psychotic symptoms, mood disturbance, or anxiety
  • 1 = with behavioral disturbance (non-specific agitation/behavioral symptoms)
  • 2 = with psychotic disturbance (hallucinations, delusions)
  • 3 = with mood disturbance (depression, lability, apathy)
  • 4 = with anxiety disturbance
  • 11 = with agitation (specific 7-character subcategory where applicable)

The highest level of specificity should always be coded. If multiple behavioral disturbances are present (e.g., both psychotic features and agitation), code the one that best reflects the predominant clinical presentation or that the provider specifically documents. Per CMS/NCHS ICD-10-CM Tabular, only one behavioral disturbance 6th character may be assigned per dementia code.

Coding Clinic Guidance on Severity Documentation

Severity must be clinically documented by the treating provider — coders may not infer severity from functional assessment scores alone without physician attestation. When severity is not specified, assign the “unspecified” (9) severity subcategory (e.g., F03.90). Query the provider when documented clinical findings (CDR score, MMSE/MoCA, functional status) suggest a severity level that is not explicitly stated. See the AHA Coding Clinic section below for specific guidance citations.

🔢 ICD-10-CM Code Set (FY2026)

Alzheimer’s Disease (Code First — G30.x)

Vascular Dementia (F01.5x — Combination Codes)

Dementia in Diseases Classified Elsewhere (F02.8x — Manifestation Code)

Unspecified Dementia (F03.9x)

Related Degenerative and Neurological Codes

🔎 Indexing

The following ICD-10-CM Alphabetic Index pathways guide coders to correct code selection. Always verify in the Tabular List and confirm with FY2026 code tables.

🏥 CPT (2026)

The following CPT codes are commonly used in the evaluation, diagnosis, and cognitive assessment of dementia patients.

🧾 HCPCS (2026)

Note on oral cholinesterase inhibitors (donepezil, galantamine, rivastigmine oral/patch): These are typically covered under Medicare Part D and billed via NDC through the pharmacy benefit. They do not have separately billable HCPCS J-codes under Part B in standard outpatient settings except in specific circumstances (e.g., rivastigmine patch in select DME/home health contexts). Coders should document medication reconciliation to support MEAT criteria for HCC coding purposes.

📚 AHA Coding Clinic (Recent Guidance)

💰 HCC / Risk Adjustment (v28)

Dementia is one of the highest-impact conditions in the CMS-HCC Model v28 (effective for Medicare Advantage risk adjustment beginning payment year 2024, phasing in through 2026). The distinction between HCC 124 and HCC 125 — driven entirely by the presence or absence of behavioral/neuropsychiatric disturbance — has direct financial implications for Medicare Advantage plans and providers in value-based contracts.

HCC Mapping Table

RAF Impact Analysis

The RAF differential between HCC 124 and HCC 125 represents approximately +0.192 RAF points per patient per year. For a Medicare Advantage plan with 1,000 dementia patients, correct capture of behavioral disturbances — where clinically documented — translates to a potential RAF impact of $192,000+ annually (at ~$1,000/RAF point) when comparing comprehensive vs. incomplete documentation capture.

HCC Hierarchies and Interactions

In CMS-HCC v28, HCC 124 (Dementia With Complications) supersedes HCC 125 (Dementia Without Complication) — if HCC 124 is assigned, HCC 125 is suppressed in the same payment year. Coders should always assign the most specific code that reflects the documented clinical picture; if behavioral disturbance is documented, assign HCC 124-mapping codes and HCC 125 will be dropped from the calculation per HCC hierarchical rules.

MEAT Documentation Requirements

For annual risk adjustment coding, dementia codes must satisfy MEAT criteria (Monitor, Evaluate, Assess/Address, Treat). Documentation should include:

• Monitor: Serial cognitive assessments (MMSE, MoCA, CDR); caregiver status reports; functional decline tracking
• Evaluate: Neurological examination findings; neuropsychiatric inventory (NPI) scoring; laboratory or imaging results
• Assess/Address: Clinical decision-making regarding medication changes, care setting, safety planning
• Treat: Active medication management (AChEI, memantine, behavioral medications); non-pharmacological interventions; referrals

✍️ CDI Query Templates

All queries below follow AHIMA/ACDIS compliant format: non-leading, multiple-choice, clinically grounded. Queries should be accompanied by supporting clinical findings from the medical record.

🧑‍⚕️ Treatments (Clinical)

This section provides a clinical overview of dementia management to support CDI teams in understanding the therapeutic context behind documentation and care plans.

Pharmacological Management by Dementia Type

Alzheimer’s Disease

• Mild-to-moderate AD: Cholinesterase inhibitors (donepezil 5–10mg, rivastigmine 3–6mg BID or 4.6–9.5mg/24h patch, galantamine 8–24mg); clinical effect modest but statistically significant per Cochrane reviews
• Moderate-to-severe AD: Memantine 5–20mg added to AChEI (combination therapy); addresses NMDA excitotoxicity
• Early AD (MCI due to AD / mild AD dementia): Lecanemab (Leqembi) 10mg/kg IV q2w; donanemab (Kisunla) 700mg IV monthly (dose-titratable); both require amyloid confirmation; amyloid-related imaging abnormalities (ARIA) monitoring with serial MRI

Vascular Dementia

No FDA-approved disease-specific pharmacotherapy. Management focuses on aggressive vascular risk factor reduction: antihypertensive therapy (target BP <130/80 per AHA/ACC guidelines), antiplatelet agents (aspirin, clopidogrel), statin therapy, glycemic control in diabetes. AChEIs have limited evidence for vascular dementia but are used off-label in mixed dementia (AD + vascular).

Dementia with Lewy Bodies

Rivastigmine is the most evidence-supported AChEI for DLB. Avoid antipsychotics (especially typical) — severe neuroleptic sensitivity reactions can be fatal in DLB. If antipsychotic is necessary, quetiapine at lowest effective dose with extreme caution. Treat REM sleep behavior disorder with clonazepam or melatonin.

Frontotemporal Dementia

No FDA-approved pharmacotherapy. AChEIs may worsen behavioral symptoms in FTD and are generally contraindicated. SSRIs (sertraline, fluvoxamine) used for disinhibition and compulsive behaviors; trazodone for agitation/insomnia; antipsychotics for severe behavioral symptoms.

Non-Pharmacological / Multidisciplinary Approaches

• Cognitive Rehabilitation: Compensatory strategies (memory aids, structured routines) for mild-to-moderate stages
• Occupational Therapy: ADL training, home safety assessment, adaptive equipment
• Speech-Language Pathology: Dysphagia management (common in advanced dementia), communication strategies
• Physical Therapy: Fall prevention, gait training, maintenance of mobility
• Caregiver Support Programs: Psychoeducation, respite care, support groups; reduces caregiver burden and delays nursing home placement
• Advance Care Planning: Early discussion of goals of care, POLST/MOLST, durable power of attorney for healthcare; particularly important given progressive nature of disease

Care Setting Considerations

Dementia management spans community (primary care, geriatric clinics), memory centers (specialized dementia care units), post-acute (SNF/NF for subacute rehabilitation or long-term care), and hospice settings. Each care setting has distinct coding, billing, and documentation requirements. Memory care units in residential settings may use specialized assessment tools (MDS for SNF RAI process) that generate coding data for ICD-10-CM assignment.

🎓 Patient Education / Summary

The following patient-oriented summary is designed to assist clinical documentation specialists and coders in understanding how patients and caregivers describe their conditions — and to help identify documentation opportunities from patient-reported history.

What Is Dementia?

Dementia is a general term for a group of symptoms affecting memory, thinking, behavior, and the ability to perform everyday activities. It is caused by damage to brain cells and is not a normal part of aging. According to the Alzheimer’s Association, approximately 55 million people worldwide live with dementia, and the condition is the 7th leading cause of death globally.

Common Questions Patients and Caregivers Ask

• “What type of dementia does my family member have?” — The answer (Alzheimer’s, vascular, Lewy body, etc.) is critical for code assignment. If the chart lacks a specific type, CDI should query.
• “How bad is the dementia right now?” — Severity (mild/moderate/severe) must be documented by the provider. Caregiver description of functional decline can support but not replace physician documentation.
• “Is the agitation/wandering/paranoia part of the dementia?” — Provider attribution of behavioral symptoms to the dementia is required to capture the behavioral disturbance 6th character. Nursing documentation of these symptoms alone does not support code assignment without physician acknowledgment.
• “Are there new treatments?” — For patients asking about lecanemab or donanemab, they must have early-stage Alzheimer’s with confirmed amyloid pathology. This is a CDI opportunity: confirm early AD diagnosis, mild severity code, and amyloid confirmation documentation.

Key Patient Education Points

• Dementia is a progressive condition; there is currently no cure, but treatments can slow symptoms or modify disease course
• Early diagnosis is important for access to treatments (anti-amyloid therapies for early AD) and care planning
• The National Institute on Aging provides free patient and caregiver education resources
• Safety planning (wandering, driving cessation, medication management, fall prevention) is a core component of dementia care
• Caregiver burden is a recognized clinical concern; caregivers should be screened and supported as part of comprehensive dementia care
• Advance care planning conversations should begin early, while the patient has decision-making capacity

Documentation Takeaway for CDI

From a clinical documentation standpoint, every dementia encounter is an opportunity to capture: (1) the specific underlying etiology, (2) the current severity, (3) any behavioral or neuropsychiatric manifestations, and (4) the active treatment plan. These four elements together ensure the most accurate ICD-10-CM code selection, support HCC 124 vs. HCC 125 differentiation, and satisfy MEAT criteria for risk adjustment. When any element is missing from the documentation, a compliant CDI query is appropriate.

About this Guide

This Clinical Documentation Guide is published by CCO Academy and is intended for credentialed coding, CDI, and clinical documentation professionals. Content is updated for FY2026 ICD-10-CM (effective October 1, 2025). All code assignments should be verified against the official ICD-10-CM Tabular List, AHA Coding Clinic, and applicable payer-specific policies. This guide does not constitute legal, medical, or compliance advice.

Last reviewed: April 2026 · Next scheduled review: October 2026 (FY2027 update)