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G35.B2

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🧬 ICD-10 CM G35.B2 — Non-Active Primary Progressive Multiple Sclerosis

Billable Code Confirmed

ICD-10-CM G35.B2 is a valid, billable 5-character ICD-10-CM code for FY2026. The first three characters (G35) define the category of Multiple Sclerosis, the fourth character (B) specifies Primary progressive multiple sclerosis, and the fifth character (2) defines the specific activity status as non-active. No additional characters are required.

Non-Billable Parent Codes — Never Submit These

  • ❌ G35 — 3-character header — Lacks phenotype specificity (retired as a valid primary diagnosis as of FY2026).
  • ❌ G35.B — 4-character header — Lacks activity status specificity.

Always submit G35.B2 (all 5 characters) when primary progressive multiple sclerosis is clinically documented without evidence of inflammatory disease activity.

Clinical Context: Phenotype and Activity Status

ICD-10 CM G35.B2 captures primary progressive multiple sclerosis (PPMS) during a period where there is no clinical or MRI evidence of new inflammatory activity (non-active). This specificity matters because it distinguishes the stable or purely neurodegenerative phase of PPMS from periods with active relapses or new lesions, which drives different treatment protocols and accurate documentation.

Code Classification

ICD-10-CM Diagnosis Code — wRVU, assistant payable, and global period fields are not applicable; direct reader to Commonly Associated CPT Codes and ICD-10-PCS Crosswalk sections for procedural alignments.

🔍 Code Description

ICD-10 CM G35.B2 classifies non-active primary progressive multiple sclerosis. This code represents patients with a baseline progressive disease course from onset (primary progressive) who are currently not exhibiting signs of active central nervous system inflammation, such as new or enlarging T2 lesions on MRI or acute clinical relapses.

Multiple sclerosis is characterized by the autoimmune-mediated destruction of myelin in the central nervous system. In primary progressive MS, patients experience a steady decline in physical and cognitive function rather than the distinct attacks seen in relapsing-remitting forms. Accurate code selection requires clinical documentation confirming both the PPMS phenotype and the lack of current inflammatory activity.

🌳 Code Tree / Hierarchy

G35 Multiple sclerosis ❌ Non-billable
│
├── G35.A Relapsing-remitting multiple sclerosis ✅ Billable
├── G35.B Primary progressive multiple sclerosis ❌ Non-billable
│ │
│ ├── G35.B0 Primary progressive multiple sclerosis, unspecified ✅ Billable
│ ├── G35.B1 Active primary progressive multiple sclerosis ✅ Billable
│ └── G35.B2 Non-active primary progressive multiple sclerosis ◀ THIS CODE ✅ Billable
│
├── G35.C Secondary progressive multiple sclerosis ❌ Non-billable
│ │
│ ├── G35.C0 Secondary progressive multiple sclerosis, unspecified ✅ Billable
│ ├── G35.C1 Active secondary progressive multiple sclerosis ✅ Billable
│ └── G35.C2 Non-active secondary progressive multiple sclerosis ✅ Billable
│
└── G35.D Multiple sclerosis, unspecified ✅ Billable

Phenotype Specificity Coding Insight

For FY2026, blanket coding of MS under the old G35 code will lead to claim denials or delays. You must query the provider if the medical record identifies “Multiple Sclerosis” without specifying the phenotype (relapsing-remitting vs. progressive) and the activity level (active vs. non-active).

✅ Includes

The following clinical terms and scenarios map to G35.B2 when documented:

  • Primary progressive multiple sclerosis without evidence of inflammatory disease activity
  • Non-active primary progressive MS

❌ Excludes

Excludes 1 — Cannot Be Coded Simultaneously with G35.B2

CodeDescriptionNote
G36.0Neuromyelitis optica [Devic]Clinically distinct demyelinating syndrome targeting optic nerves and spinal cord; mutually exclusive with MS.
G37.3Acute transverse myelitis in demyelinating disease of central nervous systemDemyelination restricted to the spinal cord; mutually exclusive when part of a separate demyelinating disease classification.

Excludes 1 Violation Risk

A common error is attempting to code multiple distinct demyelinating syndromes simultaneously. If a patient’s diagnosis evolves from isolated transverse myelitis to confirmed primary progressive multiple sclerosis, code only the definitive MS code (G35.B2).

Excludes 2 — May Be Coded in Addition if Separately Present

CodeDescriptionNote
N/ANo specific Excludes 2 notes apply directly to this subcategory.N/A

📋 Clinical Overview

Phenotype and Activity Distinction

Accurate capture relies on parsing the specific disease trajectory and recent imaging findings from the neurology notes.

FeatureG35.B2 — Non-Active PPMSG35.B1 — Active PPMSG35.A — Relapsing-Remitting MS
Disease OnsetGradual worsening from onset.Gradual worsening from onset.Distinct attacks with recovery periods.
Current Inflammatory ActivityNo (Stable MRI, no acute relapse).Yes (New/enlarging MRI lesions or acute relapse).Varies; episodic flares.
Treatment FocusSymptom management, physical therapy.Disease-modifying therapies (DMTs), steroids.Disease-modifying therapies (DMTs), steroids.

CDI Query Trigger — Specificity Missing

If the provider documents “PPMS” but does not indicate whether there is active inflammation or stability in recent MRIs, query for activity status to accurately select between G35.B1 and G35.B2. Defaulting to G35.B0 (unspecified) should be avoided when data is available.

Manifestations & Symptom Burden

Always code the documented manifestations to fully capture the patient’s complexity. Common manifestations for PPMS include:

  • Mobility Impairments: Spasticity, muscle weakness, or ataxia.
  • Sensory Disturbances: Paresthesias, numbness, or loss of sensation.
  • Visual Deficits: Optic neuritis, visual loss, or extra-ocular movement disorders.
  • Autonomic Dysfunction: Bladder dysfunction or bowel irregularities.

Coding Manifestations

Examples of coding MS manifestations:

  • G82.20 — Paraplegia, unspecified
  • R27.0 — ataxia, unspecified
  • N31.9 — Neuromuscular dysfunction of bladder, unspecified

💰 HCC Risk Adjustment (CMS-HCC v28)

FieldDetail
CMS-HCC Model Versionv28 (2024-2025 Implementation)
HCC Assignment✅ Mapped — HCC 198
HCC CategoryHCC 198 — Multiple Sclerosis
RAF Coefficient~0.450 - 0.500 (varies by demographic/status)

G35.B2 maps directly to an HCC and contributes to the RAF score.

Capture Annually

MS is a chronic, lifelong condition. Even though G35.B2 indicates a “non-active” state of inflammation, the progressive nature of the disease persists. It must be captured at least once every calendar year during a face-to-face encounter to ensure accurate risk adjustment and care management funding.

🏥 DRG Assignment

MDC 01 — Diseases and Disorders of the Nervous System

DRGTitleEst. Relative Weight*
DRG 058MULTIPLE SCLEROSIS AND CEREBELLAR ATAXIA with MCC~1.50 - 1.80
DRG 059MULTIPLE SCLEROSIS AND CEREBELLAR ATAXIA with CC~1.00 - 1.20
DRG 060MULTIPLE SCLEROSIS AND CEREBELLAR ATAXIA without CC/MCC~0.70 - 0.90

Approximate. Verify against IPPS FY2026 Final Rule tables.

Sequencing and Complications

If admitted specifically for an exacerbation of MS manifestations (e.g., severe spasticity requiring inpatient management), G35.B2 is sequenced as principal. If admitted for a complication unrelated to MS (e.g., pneumonia), G35.B2 is sequenced secondarily. Note that if a patient with non-active PPMS develops acute activity, the code must be updated to an active code (e.g., G35.B1).

🔗 Related ICD-10-CM Codes

Phenotype Variants

CodeDescription
G35.ARelapsing-remitting multiple sclerosis
G35.B1Active primary progressive multiple sclerosis
G35.C2Non-active secondary progressive multiple sclerosis

🛠️ Commonly Associated CPT Codes (Outpatient / Profee)

Outpatient Setting Context

Non-active PPMS patients frequently present for routine monitoring, symptom management, and physical rehabilitation evaluations.

CPT CodeDescriptionProfee Coding Notes (Modifier 26)
99214Office or other outpatient visit, established patientFrequent E/M level for complex chronic monitoring.
95860Needle electromyography, one extremityUsed for evaluating muscle weakness or spasticity.
92081Visual field examination, limitedRoutine monitoring of optic nerve function.
97110Therapeutic procedure, 1 or more areas, each 15 minutesStandard for physical therapy management of mobility loss.

NCCI Bundling Considerations

  • Standard E/M modifiers (e.g., Modifier -25) apply if a significant, separately identifiable evaluation and management service is provided on the same day as a minor procedural intervention (e.g., a spasticity injection).

🔬 ICD-10-PCS Crosswalk (Inpatient Procedures)

When G35.B2 is an inpatient diagnosis, these PCS codes are relevant for associated inpatient interventions, typically targeting severe symptomatic manifestations.

PCS SectionBody SystemRoot OperationClinical Application
0 (Medical and Surgical)W (Anatomical Regions, General)3 (Control)Placement of a percutaneous feeding tube (e.g., 0WJG3ZZ) if severe dysphagia develops.
F (Physical Rehabilitation)0 (Rehabilitation)9 (Assessments)Physical therapy assessment of motor/nerve function (e.g., F01Z4EZ).

💊 Coding Scenarios and Examples

Scenario 1 — Outpatient Neurology: Routine Follow-Up

Clinical Vignette: A 48-year-old female presents for a routine 6-month follow-up of her primary progressive multiple sclerosis. She reports a slow but steady decline in her walking distance over the past year. Recent brain and cervical spine MRIs show stable demyelinating plaques with no gadolinium-enhancing lesions. Her neurologist assesses her as stable without current inflammatory activity and adjusts her physical therapy orders.

CPT / HCPCS (Profee):

  • 99214 — Office/outpatient visit, established patient, moderate MDM.

ICD-10-CM:

  • G35.B2 — Non-active primary progressive multiple sclerosis (Correctly captures the PPMS phenotype and the lack of new inflammatory disease activity shown on MRI).

Scenario 2 — Inpatient: Secondary Diagnosis for UTI

Clinical Vignette: A 55-year-old male with a history of non-active primary progressive multiple sclerosis and a neurogenic bladder is admitted for a severe catheter-associated urinary tract infection (CAUTI) causing sepsis.

Principal Diagnosis:

  • A41.9 — Sepsis, unspecified organism (Reason for admission)

Secondary Diagnoses:

  • T83.511A — Infection and inflammatory reaction due to indwelling urethral catheter, initial encounter
  • N39.0 — Urinary tract infection, site not specified
  • G35.B2 — Non-active primary progressive multiple sclerosis (Systemic comorbidity influencing patient care and baseline risk).
  • N31.9 — Neuromuscular dysfunction of bladder, unspecified

MS-DRG Assignment: The presence of Sepsis acts as the principal diagnosis grouping to MDC 18. G35.B2 acts as a chronic comorbidity that supports the medical necessity of the complex admission but does not function as a CC/MCC for the Sepsis DRG grouping on its own.

Scenario 3 — CDI Query: Missing Activity Status

Clinical Vignette: The provider’s discharge summary states: “Patient admitted for management of severe spasticity secondary to Primary Progressive Multiple Sclerosis. The patient had a brain MRI performed yesterday which was reviewed and showed no changes from baseline.”

Action / Outcome: The documentation lacks explicit confirmation of the disease’s “activity” status, although the “no changes from baseline” MRI strongly implies a non-active state. A CDI query should be placed to clarify the specific activity status of the PPMS for accurate code assignment.

Query Response: Provider updates documentation to state: “Primary Progressive Multiple Sclerosis, non-active based on stable MRI.”

Corrected ICD-10-CM Coding:

  • G35.B2 — Non-active primary progressive multiple sclerosis.

⚠️ Coding Pitfalls and Tips

Pitfall or Tip
❌Using the retired 3-character header. Defaulting to the historical G35 code for dates of service after October 1, 2025, will result in immediate claim denials. You must code to the 4th or 5th character.
❌Assuming “unspecified” when data exists. Do not default to G35.B0 (Primary progressive MS, unspecified) if the medical record contains clear language or MRI findings that confirm active or non-active status. Query if ambiguous.
✅Code all manifestations. Always capture secondary codes for specific symptoms (e.g., neurogenic bladder, ataxia, paraplegia) to thoroughly paint the picture of the patient’s severity of illness and risk of mortality.
✅Annual HCC capture. Ensure G35.B2 is documented and billed at least once a year during a face-to-face encounter to support risk-adjusted funding for the patient’s chronic condition.

📚 Sources

1. AAPC. *ICD-10-CM Code for Non-active primary progressive multiple sclerosis G35.B2*. 2. CMS. *Article - Billing and Coding: Visual Electrophysiology Testing (A57060)*. 3. ICD10Data. *2026 ICD-10-CM Diagnosis Code G35.B2: Non-active primary progressive multiple sclerosis*. 4. Infusion Access Foundation. *Big ICD-10 Changes for Multiple Sclerosis—What Patients Need to Know*. 5. Sprypt. *ICD-10 Code G35: Multiple Sclerosis 2025 Essential Medical Billing updates*. 6. McBee Associates. *It's That Time Again: Preparing for the New ICD-10-CM Codes*.

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