What alternative ICD-10 (International Classification of Diseases, 10th Revision) codes can be used for a patient with advancing dementia, as F03.90 is not a covered diagnosis?

Alternative ICD-10 Codes for Advancing Dementia

When F03.90 (unspecified dementia without behavioral disturbance) is not covered, use etiology-specific codes with behavioral disturbance modifiers, particularly F02.81 (dementia in other diseases classified elsewhere with behavioral disturbance) or F01.51 (vascular dementia with behavioral disturbance), which typically have better insurance coverage. 1

Primary Alternative Coding Strategy

The key to obtaining coverage is documenting the underlying pathology rather than using unspecified dementia codes. The specific F code must match the established etiology:

Alzheimer's Disease Dementia

• F02.81: Dementia in other diseases classified elsewhere with behavioral disturbance 1
• F02.80: Dementia in other diseases classified elsewhere without behavioral disturbance 1
• Must be paired with G30.9 (Alzheimer's disease, unspecified) as the primary disease code 1
• The G30 code must be listed first, followed by the F02 code 1

Vascular Dementia

• F01.51: Vascular dementia with behavioral disturbance 1
• F01.50: Vascular dementia without behavioral disturbance 1
• Use when cerebrovascular disease is the primary etiology 1

Mixed Etiology Dementia

• F02.81 with documentation of all contributing pathologies 1
• The primary disease code must be listed first, followed by F02.81 1
• Requires validated assessment tools (NPI-Q, CMAI, CSDD, GAI, or PSWQ-A) to document behavioral symptoms 1

Critical Documentation Requirements

Behavioral disturbance codes (.81 or .51) typically have better coverage than non-behavioral codes because they justify more intensive management. 1 Document any of these symptoms to support behavioral disturbance coding:

• Agitation, aggression, or wandering 1
• Sexual disinhibition 1
• Mood fluctuations or apathy 1
• Social withdrawal or socially unacceptable behaviors 1
• Visual hallucinations (particularly in Lewy body dementia) 1

When Specific Etiology Cannot Be Established

If diagnostic evaluation has been completed but specific pathology cannot be definitively established, unspecified codes may be appropriate: 1

• F03.91: Unspecified dementia with behavioral disturbance (alternative to F03.90)
• Use when mixed etiology is present but no single pathology predominates 1
• Use for atypical or non-amnestic symptoms that don't fit standard diagnostic criteria 1

Practical Coding Pitfalls to Avoid

The most common error is using F03.90 when a specific etiology has been established. 2 Alzheimer's disease is grossly undercoded in clinical practice, with only 13% of patients receiving AD therapy having AD as the primary diagnosis. 2

Medicare carriers consider 290 series codes (senile dementia) as mental health codes and reimburse them at lower rates than medical codes. 2 This creates a financial disincentive that contributes to undercoding.

Always establish the underlying pathology through appropriate diagnostic evaluation including cognitive assessment (MMSE, MoCA, 3MS, RUDAS), functional assessment (DAD, FAST, FAQ), and neuroimaging when indicated. 3 The modern biological definition uses biomarkers including amyloid-beta (PET, CSF, plasma) and hyperphosphorylated tau (p-tau 217, p-tau 181, p-tau 231). 4

Recommended Action Steps

1. Review the patient's diagnostic workup to identify specific etiology (Alzheimer's, vascular, Lewy body, frontotemporal) 4
2. Document behavioral symptoms using validated tools to justify .81 or .51 codes 1
3. Use dual coding with primary disease code (G30.9 for Alzheimer's) followed by F02.81 1
4. If truly unspecified, consider F03.91 (with behavioral disturbance) instead of F03.90 1
5. Contact the insurance company to determine which specific F codes are covered in their formulary