Skip to main content

G35.B1 ICD-10-CM Code: Active primary progressive multiple sclerosis

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
1 inclusion term
Risk adjustment
CMS-HCC V28: 1 category · CMS-HCC V22 category 77 · RxHCC V08 category 159

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 058 — MULTIPLE SCLEROSIS AND CEREBELLAR ATAXIA WITH MCC (MDC 01)
  • MS-DRG 059 — MULTIPLE SCLEROSIS AND CEREBELLAR ATAXIA WITH CC (MDC 01)
  • MS-DRG 060 — MULTIPLE SCLEROSIS AND CEREBELLAR ATAXIA WITHOUT CC/MCC (MDC 01)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Risk Adjustment (CMS-HCC)

Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.

  • HCC 198 — Multiple Sclerosis

Other models: CMS-HCC V22 HCC 77 · RxHCC V08 HCC 159

Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for G35.B1 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Primary progressive multiple sclerosis with evidence of inflammatory disease activity

Code Overview

Active primary progressive multiple sclerosis is a billable ICD-10-CM diagnosis code (G35.B1).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (2)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name G35.B1 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: G37.3 — Acute transverse myelitis in demyelinating disease of central nervous system (via G35.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 1 Excludes2 note: G04 — Encephalitis, myelitis and encephalomyelitis (via G35.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

Referenced by 2 Code First instructions: F02 — Dementia in other diseases classified elsewhere (via G35.-), F48.2 — Pseudobulbar affect (via G35.-).

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 3 MS-DRGs: DRG 058 (MDC 01), DRG 059 (MDC 01), DRG 060 (MDC 01).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):NVS005 — Multiple sclerosis (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Multiple Sclerosis) for risk-adjusted payment.

G35 — Multiple sclerosis, G35.A — Relapsing-remitting multiple sclerosis, G35.B0 — Primary progressive multiple sclerosis, unspecified, G35.B2 — Non-active primary progressive multiple sclerosis, G35.C0 — Secondary progressive multiple sclerosis, unspecified, G35.C1 — Active secondary progressive multiple sclerosis, G35.C2 — Non-active secondary progressive multiple sclerosis, G35.D — Multiple sclerosis, unspecified, G36.0 — Neuromyelitis optica [Devic], G36.1 — Acute and subacute hemorrhagic leukoencephalitis [Hurst], G36.8 — Other specified acute disseminated demyelination, G36.9 — Acute disseminated demyelination, unspecified, G37.0 — Diffuse sclerosis of central nervous system, G37.1 — Central demyelination of corpus callosum, G37.2 — Central pontine myelinolysis, G37.5 — Concentric sclerosis [Balo] of central nervous system, G37.81 — Myelin oligodendrocyte glycoprotein antibody disease, G37.89 — Other specified demyelinating diseases of central nervous system, G37.9 — Demyelinating disease of central nervous system, unspecified

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Multiple sclerosis).

G35 — Multiple sclerosis, G35.A — Relapsing-remitting multiple sclerosis, G35.B0 — Primary progressive multiple sclerosis, unspecified, G35.B2 — Non-active primary progressive multiple sclerosis, G35.C0 — Secondary progressive multiple sclerosis, unspecified, G35.C1 — Active secondary progressive multiple sclerosis, G35.C2 — Non-active secondary progressive multiple sclerosis, G35.D — Multiple sclerosis, unspecified

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Sclerosis, sclerotic”; these codes share that main term but sit in a different category of the Tabular List.

A52.11 — Tabes dorsalis (spinal, posterior), E27.8 — Other specified disorders of adrenal gland (adrenal), E31.8 — Other polyglandular dysfunction (polyglandular), E72.09 — Other disorders of amino-acid transport (renal, with, cystine storage disease), E75.23 — Krabbe disease (brain, Krabbe's), G11.11 — Friedreich ataxia (Friedreich's), G11.9 — Hereditary ataxia, unspecified (hereditary, cerebellar), G12.21 — Amyotrophic lateral sclerosis (lateral), G12.23 — Primary lateral sclerosis (primary, lateral), G25.9 — Extrapyramidal and movement disorder, unspecified (extrapyramidal), G37.0 — Diffuse sclerosis of central nervous system (diffuse), G37.5 — Concentric sclerosis [Balo] of central nervous system (concentric), G37.9 — Demyelinating disease of central nervous system, unspecified (brain), G61.0 — Guillain-Barre syndrome (spinal, ascending), G93.81 — Temporal sclerosis (temporal), G95.89 — Other specified diseases of spinal cord (spinal), H35.00 — Unspecified background retinopathy (retina), I05.8 — Other rheumatic mitral valve diseases (mitral), I07.8 — Other rheumatic tricuspid valve diseases (tricuspid), I25.10 — Atherosclerotic heart disease of native coronary artery without angina pectoris (coronary), +29 more

Contextual Map

Every relationship of G35.B1 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run G35.B1 with these 4 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

Referenced by Excludes2 notes

Referenced by Code First instructions

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

  • HCC 198 — Multiple Sclerosis [CMS-HCC]— CMS-HCC V28 · 2026

MS-DRG Grouper

MDC crossing

  • MDC 01 — Diseases and Disorders of the Nervous System[MDC crossing]: “Diseases and Disorders of the Nervous System — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 8,892 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

  • Sclerosis, sclerotic, multiple (brain stem) (cerebral) (disseminated) (generalized) (spinal cord), progressive, primary, active[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Sclerosis, sclerotic, multiple (brain stem) (cerebral) (disseminated) (generalized) (spinal cord), progressive, primary, with, evidence of inflammatory disease activity[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (10)

Change history

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Risk adjustment Official source data
2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "G35.B1 — Active primary progressive multiple sclerosis." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/g35.b1-active-primary-progressive-multiple-sclerosis

Change history

  • FY2026 — October 1, 2025
    Added to the code set
    Active primary progressive multiple sclerosis
    FY2026 changes

Nearest Codes in This Family

Official ICD-10-CM classifications closest to G35.B1 in its code family, with their registry titles.

View all codes in the G35 family