G35.B0 ICD-10-CM Code: Primary progressive multiple sclerosis, unspecified
HCC Buddy Code Card
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FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Demyelinating diseases of the central nervous system (G35-G37)
G35.B0
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidancePrimary progressive multiple sclerosis, unspecified
Primary progressive multiple sclerosis, unspecified, is a form of MS where symptoms gradually worsen from the onset without distinct relapses and remissions.
CMS-HCC V28
MappedHCC 198
RAF 0.0
CMS-HCC V24
00
RAF 0
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 77
RAF 0.0
RXHCC
MappedHCC 159
RAF 0.0
Code Trumping
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Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for G35.B0 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for G35.B0 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for G35.B0 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for G35.B0 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for G35.B0 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for G35.B0 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for G35.B0 in this effective period.
Buddy Documentation Tip
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is G35.B0 an HCC code?
Yes. G35.B0 maps to Multiple Sclerosis under the CMS-HCC V28 risk adjustment model.
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for G35.B0
For G35.B0to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed G35.B0 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
G35.B0 is the ICD-10-CM diagnosis code for primary progressive multiple sclerosis, unspecified. Primary progressive multiple sclerosis, unspecified, is a form of MS where symptoms gradually worsen from the onset without distinct relapses and remissions. G35.B0 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering demyelinating diseases of the central nervous system (g35-g37).
Under the CMS-HCC V28 risk adjustment model, G35.B0 maps to Multiple Sclerosis (HCC 198) with a community, non-dual, aged base RAF weight of 0.000. G35.B0 was not retained as a payment HCC under the older V24 model, so V28 introduced or recategorized it during the 2024–2026 phase-in. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Use this code when primary progressive MS is documented but activity status (active vs. non-active) is not specified. Because G35.B0 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for G35.B0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.