HCC 198: Multiple Sclerosis ICD-10-CM
CMS-HCC Category 198 (Multiple Sclerosis) is a payment HCC in the V28 Medicare Advantage risk adjustment model. For payment year 2026 it adds a risk adjustment factor between 0.226 and 1.143 to a beneficiary's RAF score depending on the payment segment (0.647 for a community, non-dual, aged enrollee). 20 ICD-10-CM diagnosis codes map to HCC 198. It sits at the top of its hierarchy: no other condition category supersedes it.
RAF Weight by Payment Segment 7 segments
| Payment Segment | Relative Factor |
|---|---|
| Community, non-dual, aged | 0.647 |
| Community, partial-benefit dual, aged | 0.569 |
| Community, full-benefit dual, aged | 0.791 |
| Community, non-dual, disabled | 0.908 |
| Community, partial-benefit dual, disabled | 0.770 |
| Community, full-benefit dual, disabled | 1.143 |
| Institutional | 0.226 |
A beneficiary is scored in exactly one segment, set by Medicaid (dual) status, aged or disabled entitlement, and residence. Factors are relative weights, not dollar amounts; new-enrollee segments score on demographics only. HCC 198 neither supersedes nor is superseded by any other category, so it always counts alongside unrelated HCCs.
ICD-10-CM Codes That Map to HCC 198 20 codes
- G35 Multiple sclerosis Non-billable from V24 HCC 77
- G35.A Relapsing-remitting multiple sclerosis new to V28
- G35.B0 Primary progressive multiple sclerosis, unspecified new to V28
- G35.B1 Active primary progressive multiple sclerosis new to V28
- G35.B2 Non-active primary progressive multiple sclerosis new to V28
- G35.C0 Secondary progressive multiple sclerosis, unspecified new to V28
- G35.C1 Active secondary progressive multiple sclerosis new to V28
- G35.C2 Non-active secondary progressive multiple sclerosis new to V28
- G35.D Multiple sclerosis, unspecified new to V28
- G36.0 Neuromyelitis optica [Devic] from V24 HCC 77
- G36.1 Acute and subacute hemorrhagic leukoencephalitis [Hurst] from V24 HCC 77
- G36.8 Other specified acute disseminated demyelination from V24 HCC 77
- G36.9 Acute disseminated demyelination, unspecified from V24 HCC 77
- G37.0 Diffuse sclerosis of central nervous system from V24 HCC 77
- G37.1 Central demyelination of corpus callosum from V24 HCC 77
- G37.2 Central pontine myelinolysis from V24 HCC 77
- G37.5 Concentric sclerosis [Balo] of central nervous system from V24 HCC 77
- G37.81 Myelin oligodendrocyte glycoprotein antibody disease from V24 HCC 77
- G37.89 Other specified demyelinating diseases of central nervous system from V24 HCC 77
- G37.9 Demyelinating disease of central nervous system, unspecified from V24 HCC 77
Every code above carries the full HCC 198 weight when documented and reported on a Medicare Advantage encounter. The code link opens its full page with the complete risk adjustment card.
Questions About HCC 198
What is HCC 198 in the CMS-HCC model?
HCC 198 is CMS-HCC Category 198 (Multiple Sclerosis) in the V28 risk adjustment model. It covers 20 ICD-10-CM diagnosis codes that raise a Medicare Advantage beneficiary's risk score when documented.
What is the RAF weight for HCC 198?
For payment year 2026, HCC 198 adds 0.647 to the RAF score of a community, non-dual, aged beneficiary (living at home, age 65 or over, not also enrolled in Medicaid). The published weights range from 0.226 to 1.143 across the seven payment segments shown above.
Related References
Source: Centers for Medicare & Medicaid Services, Payment Year 2026 risk adjustment mapping and model software releases (CMS-HCC V28), applied to the FY 2026 ICD-10-CM code set. ICD List is not affiliated with CMS.
