2027 ICD-10-CM Diagnosis Code G35Multiple sclerosis

ICD-10-CM Codes›G00–G99›G35-G37›G35

ICD-10-CM G35
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G35 is a non-billable ICD-10-CM category code for multiple sclerosis, so it cannot be submitted on claims. Use a more specific code from this category instead, such as G35.A, G35.B0, G35.B1, and G35.B2. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Multiple sclerosis.

For Medicare Advantage risk adjustment, G35 maps to CMS-HCC Category 198 (Multiple Sclerosis) under the V28 model, adding a risk factor of about 0.647 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
G35
Billable Status
No — Non-Billable Category
Code Describes
Multiple sclerosis
Short Description
Multiple sclerosis
Same as the full description in the CMS dataset.
Chapter
G35-G37
Demyelinating diseases of the central nervous system

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG35-G37Demyelinating diseases of the central nervous system
CategoryG35Multiple sclerosis
This CodeG35Multiple sclerosis

Specific Coding for Multiple sclerosisOverview

Non-specific codes like G35 require more characters. Use one of these billable codes instead:

  • Use G35.A for Relapsing-remitting multiple sclerosis

  • G35.B for Primary progressive multiple sclerosis

  • Use G35.B0 for Primary progressive multiple sclerosis, unspecified

  • Use G35.B1 for Active primary progressive multiple sclerosis

  • Use G35.B2 for Non-active primary progressive multiple sclerosis

  • G35.C for Secondary progressive multiple sclerosis

  • Use G35.C0 for Secondary progressive multiple sclerosis, unspecified

  • Use G35.C1 for Active secondary progressive multiple sclerosis

  • Use G35.C2 for Non-active secondary progressive multiple sclerosis

  • Use G35.D for Multiple sclerosis, unspecified

Medicare Risk Adjustment (HCC)Billing

G35 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.

CMS-HCC V28 Category (Payment Model)
HCC 198— Multiple Sclerosis
Payment HCC · PY 2027 one of 20 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.647
community, non-dual, aged · ranges 0.226–1.143 across segments
Hierarchy
Top of its hierarchy
HCC 198 is not superseded by any other condition category
Prior Model (CMS-HCC V24)
HCC 77
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 77 · ESRD (V21): HCC 77 · ESRD (V24): HCC 77
ESRD V21 weights: 0.069 dialysis, 0.000–0.546 functioning graft · ESRD V24 weights: 0.111 dialysis, 0.042–1.113 functioning graft
Part D (RxHCC)
RxHCC 159 — Multiple Sclerosis
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G35: its own notes plus those printed at Chapter 6. A note printed at a category, block or chapter applies to every code under it.

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 6 (G00-G99) Diseases of the nervous system applies to 700 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name G35, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming G35: they are not reported together with it, unless the two conditions are unrelated.

  • G37.3 Acute transverse myelitis in demyelinating disease of central nervous system
    multiple sclerosis (G35-)

Excludes2 1

These codes carry an Excludes2 note naming G35: its condition is not part of those codes, and both may be reported when the patient has both.

  • G04 Encephalitis, myelitis and encephalomyelitis
    multiple sclerosis (G35-)

Code First 2

These codes say to code first a condition named in the note, and G35 is one of the conditions named.

  • F02 Dementia in other diseases classified elsewhere
    multiple sclerosis (G35-)
  • F48.2 Pseudobulbar affect
    multiple sclerosis (G35-)

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NVS005
Multiple sclerosis
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Multiple Sclerosis

    an autoimmune disorder mainly affecting young adults and characterized by destruction of myelin in the central nervous system. pathologic findings include multiple sharply demarcated areas of demyelination throughout the white matter of the central nervous system. clinical manifestations include visual loss, extra-ocular movement disorders, paresthesias, loss of sensation, weakness, dysarthria, spasticity, ataxia, and bladder dysfunction. the usual pattern is one of recurrent attacks followed by partial recovery (see multiple sclerosis, relapsing-remitting), but acute fulminating and chronic progressive forms (see multiple sclerosis, chronic progressive) also occur. (adams et al., principles of neurology, 6th ed, p903)

Patient EducationClinical

Multiple Sclerosis

Multiple sclerosis (MS) is a disease that affects your brain and spinal cord, also called the central nervous system. MS damages myelin, the protective coating around your nerve cells. Myelin helps nerves send messages quickly. When it's damaged, messages between your brain and body slow down or get blocked. This leads to MS symptoms.

The full article covers:

  • What is multiple sclerosis?
  • What are the types of multiple sclerosis?
  • What causes multiple sclerosis?
  • What are the symptoms of multiple sclerosis?
  • How is multiple sclerosis diagnosed?
  • What are the treatments for multiple sclerosis?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert G35 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
340 Multiple sclerosis
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026RevisedCode revised
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About G35Overview

What is the ICD-10 code for multiple sclerosis?

G35 is the ICD-10-CM category for multiple sclerosis, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is G35 (Multiple sclerosis) a billable code?

No. This is a category header that groups the codes for multiple sclerosis, and headers cannot be submitted on claims. Claims for multiple sclerosis need a more specific code from this category, such as G35.A, G35.B0, and G35.B1.

What is the ICD-9 equivalent of G35?

Under the General Equivalence Mappings, multiple sclerosis converts to ICD-9-CM 340 (multiple sclerosis). The mapping is a direct match.

What HCC is G35?

G35 (multiple sclerosis) maps to CMS-HCC Category 198 (Multiple Sclerosis), commonly written as HCC 198, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 77 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 159.

Does G35 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, G35 adds a risk adjustment factor of about 0.647 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.226 to 1.143 depending on the payment segment). HCC 198 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 198 category page.