ICD-10 G23.0
Billable / Specific HCC v28: 78 CCHallervorden-Spatz disease
About ICD-10-CM G23.0
ICD-10-CM code G23.0 represents Hallervorden-Spatz disease. This is a billable/specific code in the Nervous System chapter (block G23). The 2026 edition of ICD-10-CM G23.0 became effective on October 1, 2025.
Coding Tips for G23.0
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
G23.0 is a CMS-HCC v28 risk-adjustment code (category 78). To count for the patient Risk Adjustment Factor (RAF), document the diagnosis with MEAT language each calendar year: Monitored, Evaluated, Assessed, Treated. A diagnosis on the problem list alone does not satisfy CMS RADV audit standards. Include the diagnosis in the assessment with current status and current treatment plan.
G23.0 is designated CC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-CC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag CC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under G23.0. Per CMS ICD-10-CM Tabular 2026.
- Pigmentary pallidal degeneration
Medicare Advantage HCC Impact
Capture this diagnosis annually for accurate risk adjustment. Missed HCC captures are the #1 revenue leak in Medicare Advantage risk programs.
Inpatient DRG Impact, CC
codes Hallervorden-Spatz disease. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for G23.0
Local Coverage Determinations (LCDs) from CMS MACs that list G23.0 as a covered diagnosis.
Showing top 10 of 155 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing G23.0.
4 Cigna
5 Medicare
CPT Codes Commonly Billed with G23.0
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 95923 CMS LCD: Billing and Coding: Autonomic Function Testing CMS LCD
- 95924 CMS LCD: Billing and Coding: Autonomic Function Testing CMS LCD
- 95921 CMS LCD: Billing and Coding: Autonomic Function Testing CMS LCD
- 95922 CMS LCD: Billing and Coding: Autonomic Function Testing CMS LCD
- 92571 CMS LCD: Billing and Coding: Vestibular and Audiologic Function Studies CMS LCD
- 92568 CMS LCD: Billing and Coding: Vestibular and Audiologic Function Studies CMS LCD
- 92620 CMS LCD: Billing and Coding: Vestibular and Audiologic Function Studies CMS LCD
- 92588 CMS LCD: Billing and Coding: Vestibular and Audiologic Function Studies CMS LCD
- 92572 CMS LCD: Billing and Coding: Vestibular and Audiologic Function Studies CMS LCD
- 92579 CMS LCD: Billing and Coding: Vestibular and Audiologic Function Studies CMS LCD
Convert G23.0 to ICD-9-CM
Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.
| ICD-10 | ICD-9 | Mapping Flags |
|---|---|---|
| G23.0 | 3330 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To G23.0
Other codes in section G20-G26 (Extrapyramidal and movement disorders).
ICD-10 G23.0, Billing FAQ
Is ICD-10 code G23.0 billable? +
Yes, G23.0 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What other names or terms map to G23.0? +
ICD-10 G23.0 includes: Pigmentary pallidal degeneration.
Does G23.0 affect Medicare Advantage HCC risk adjustment? +
Yes. G23.0 maps to CMS-HCC v28 category 78. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Is G23.0 a CC or MCC for inpatient DRG? +
Yes, this code is designated as CC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
What CPT codes are commonly billed with G23.0? +
Procedures frequently paired with G23.0 include: 95923, 95924, 95921, 95922, 92571.
What ICD-9 codes does G23.0 map to? +
Per CMS GEMs, G23.0 maps to ICD-9 codes: 3330. Useful for legacy data review and historical claim analysis.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on May 31, 2026.
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