ICD-10 G35.C1
Billable / Specific HCC v28: 77Active secondary progressive multiple sclerosis
About ICD-10-CM G35.C1
ICD-10-CM code G35.C1 represents Active secondary progressive multiple sclerosis. This is a billable/specific code in the Nervous System chapter (block G35). The 2026 edition of ICD-10-CM G35.C1 became effective on October 1, 2025.
Coding Tips for G35.C1
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
G35.C1 is a CMS-HCC v28 risk-adjustment code (category 77). 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.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under G35.C1. Per CMS ICD-10-CM Tabular 2026.
- Secondary progressive multiple sclerosis with evidence of inflammatory disease activity
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.
Medicare LCD Coverage for G35.C1
Local Coverage Determinations (LCDs) from CMS MACs that list G35.C1 as a covered diagnosis.
Showing top 10 of 949 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing G35.C1.
5 Medicare
CPT Codes Commonly Billed with G35.C1
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 31570 CMS LCD: Billing and Coding: Botulinum Toxin Injections CMS LCD
- 31573 CMS LCD: Billing and Coding: Botulinum Toxin Injections CMS LCD
- J0202 CMS LCD: Billing and Coding: Instructions for Lemtrada� (alemtuzumab) When Used in the Treatment of Relapsing Multiple Sclerosis CMS LCD
- J9190 CMS LCD: Billing and Coding: Chemotherapy Agents for Non-Oncologic Conditions CMS LCD
- J9260 CMS LCD: Billing and Coding: Chemotherapy Agents for Non-Oncologic Conditions CMS LCD
- J9215 CMS LCD: Billing and Coding: Chemotherapy Agents for Non-Oncologic Conditions CMS LCD
- J1553 CMS LCD: Billing and Coding: Immune Globulin Intravenous (IVIg) CMS LCD
- 91125 CMS LCD: Billing and Coding: Pelvic Floor Dysfunction: Anorectal Manometry and EMG CMS LCD
Codes Adjacent To G35.C1
Other codes in section G35-G37 (Demyelinating diseases of the central nervous system).
ICD-10 G35.C1, Billing FAQ
Is ICD-10 code G35.C1 billable? +
Yes, G35.C1 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 G35.C1? +
ICD-10 G35.C1 includes: Secondary progressive multiple sclerosis with evidence of inflammatory disease activity.
Does G35.C1 affect Medicare Advantage HCC risk adjustment? +
Yes. G35.C1 maps to CMS-HCC v28 category 77. Capture this diagnosis annually for accurate Medicare Advantage risk score.
What CPT codes are commonly billed with G35.C1? +
Procedures frequently paired with G35.C1 include: 31570, 31573, J0202, J9190, J9260.
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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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