HCPCS Level II M1131: Degenerative Neurological Condition Documentation - OpenPayer

Summary & Overview

HCPCS Level II M1131: Degenerative Neurological Condition Documentation

HCPCS Level II code M1131 documents that a patient has a degenerative neurological condition—examples include ALS, MS, or Parkinson’s disease—diagnosed at any time before or during the episode of care. Nationally, consistent use of a dedicated HCPCS Level II diagnosis-documentation code like M1131 supports accurate clinical records, care coordination, and administrative tracking for populations with progressive neurodegenerative diseases. Key payers addressed in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise explanation of the code’s clinical intent and common sites of service, an overview of payer coverage considerations, and how the code is used in documentation workflows. The summary highlights typical service settings and the administrative role of M1131 in signaling a relevant chronic neurological diagnosis during encounters. Data not available in the input is noted where payer-specific policy details, associated taxonomies, or linked ICD‑10 codes would normally appear.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareM1131HCPCS Level IIneurologydegenerative neurological conditiondocumentationambulatory carehome healthclinical codingdiagnosis capture

Billing Code Overview

HCPCS Level II code M1131 documents that a patient has a diagnosis of a degenerative neurological condition, such as amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), or Parkinson's disease, diagnosed at any time before or during the episode of care. This code captures the presence of a relevant chronic neurodegenerative diagnosis in the medical record.

Service type: Documentation / Encounter diagnosis capture

Typical site of service: Outpatient clinics, neurology practices, home health visits, and other ambulatory settings where diagnostic history is recorded

Clinical & Coding Specifications

Clinical Context

A 68-year-old patient with progressive gait instability and muscle weakness presents to a home health agency after recent hospitalization for a fall. The admitting clinician documents a prior diagnosis of a degenerative neurological disorder such as amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), or Parkinson disease that was established before the start of home health services. The clinical workflow includes review of prior neurology consult notes and discharge summaries, verification of the diagnosis in the medical record, and documentation that the patient’s degenerative neurological condition is present and relevant to the current episode of care. This documented diagnosis is used by the billing department to support use of HCPCS Level II code M1131 for agencies and payors that require explicit documentation of a degenerative neurologic condition during the episode. Clinical team members involved include the admitting nurse, home health physician or medical director, physical and occupational therapists, and medical records staff who ensure the problem list and charting explicitly state the diagnosis and its relevance to plan of care and skilled services.

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural services	When the work required to document or provide services for a patient with a complex degenerative neurologic condition is substantially greater than typical

HCPCS Level II M1139: Ongoing Care Not Indicated, Early Self-Discharge

HCPCS-M1130-PATIENT-SELF-DISCHARGE-EARLY-TERMINATION-OF-CARE

HCPCS M1130: Ongoing Care Interrupted by Patient Self-Discharge

HCPCS-M1121-EPISODE-OF-CARE-START

HCPCS M1121: Start of Episode of Care

HCPCS-M1141-FUNCTIONAL-STATUS-NOT-MEASURED-OKS-KOOS-JR-1-YEAR

HCPCS M1141: Functional Status Not Measured by OKS or KOOS, JR. at 1 Year

HCPCS-M1133-INTERRUPTED-ONGOING-CARE-DUE-TO-HOSPITALIZATION-OR-SURGERY

HCPCS Level II M1133: Interrupted Ongoing Care Due to Hospitalization or Surgery

HCPCS-LEVEL-II-M1120-PATIENT-SELF-DISCHARGED-EARLY

HCPCS Level II M1120: Ongoing Care Not Possible Due to Patient Self-Discharge

HCPCS-M1134-SELF-DISCHARGED-ONGOING-CARE-NOT-POSSIBLE

HCPCS M1134: Ongoing Care Not Possible Due to Patient Self-Discharge

HCPCS-M1132-ONGOING-CARE-NOT-CLINICALLY-INDICATED-HOME-PROGRAM-OR-REFERRAL

HCPCS M1132: Ongoing Care Not Clinically Indicated

HCPCS-M1112-DEGENERATIVE-NEUROLOGICAL-DIAGNOSIS-DOCUMENTATION

HCPCS Level II M1112: Documentation of Degenerative Neurological Diagnosis

HCPCS-M1143-NECK-REHABILITATION-INITIATION

HCPCS M1143: Initiation of Neck Rehabilitation Episode

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Taxonomy Code	Specialty	Notes
`207Q00000X`	Physical Medicine & Rehabilitation Physician	Commonly manages functional decline related to ALS, MS, Parkinson disease and coordinates home-based rehab services
`207K00000X`	Neurology	Specialty diagnosing and managing degenerative neurologic conditions documented for `M1131`
`222P00000X`	Physical Therapist	Provides evaluation and therapy services to maintain function in patients with degenerative neurologic diseases
`325600000X`	Home Health Agency	Organization taxonomy representing the agency that documents the diagnosis and delivers skilled home care services
`363A00000X`	Occupational Therapist	Provides ADL-focused interventions for patients with progressive neurologic impairment

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`G12.21`	Amyotrophic lateral sclerosis	Representative degenerative motor neuron disease commonly documented as qualifying for `M1131` when present prior to or during the episode
`G35`	Multiple sclerosis	Chronic demyelinating disease that frequently qualifies as a degenerative neurologic diagnosis for home health and related documentation
`G20`	Parkinson disease	Progressive movement disorder that is a commonly documented degenerative neurologic condition relevant to home health care
`G12.22`	Progressive muscular atrophy	Motor neuron disease variant that may be documented when assessing eligibility and care complexity
`G10`	Huntington disease	Hereditary degenerative neurologic condition that may be present and relevant to care planning

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`97161`	Physical therapy evaluation, low complexity	Initial PT assessment commonly performed to document functional deficits in patients with degenerative neurologic conditions during home health episodes
`97162`	Physical therapy evaluation, moderate complexity	Used when PT evaluation identifies multiple deficits or moderate complexity needs related to neurologic disease
`97110`	Therapeutic exercises to develop strength and endurance, range of motion and flexibility	Frequently provided by PT to address deficits from ALS, MS, or Parkinson disease during the episode of care
`97530`	Therapeutic activities, direct (one-on-one)	Functional activity training for transfers and ADLs commonly employed for patients with progressive neurologic disorders
`99341`	Home visit for new patient, typically 20 minutes	Initial physician home visit codes used when a clinician documents the qualifying neurologic diagnosis during a home health admission

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