2026 ICD-10-CM Diagnosis Code M47.011Anterior spinal artery compression syndromes, occipito-atlanto-axial region

ICD-10-CM Codes›M00–M99›M45-M49›M47

ICD-10-CM M47.011
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M47.011 is a billable ICD-10-CM diagnosis code for anterior spinal artery compression syndromes, occipito-atlanto-axial region. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 551 through 552. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 22 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Spondylopathies/spondyloarthropathy (including infective).

Code Identity

ICD-10-CM Code
M47.011
Billable Status
Yes — Valid for Submission
Code Describes
Anterior spinal artery compression syndromes, occipito-atlanto-axial region
Short Description
Anterior spinal artery comprsn synd, occipt-atlan-ax region
Parent Code
M47.01
Anterior spinal artery compression syndromes

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM45-M49Spondylopathies
CategoryM47Spondylosis
This CodeM47.011Anterior spinal artery compression syndromes, occipito-atlanto-axial region

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

CCSR MUS011
Spondylopathies/spondyloarthropathy (including infective)
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Neck Injuries and Disorders

Any part of your neck - muscles, bones, joints, tendons, ligaments, or nerves - can cause neck problems. Neck pain is very common. Pain may also come from your shoulder, jaw, head, or upper arms.

Read the full article at MedlinePlus

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

Convert M47.011 to ICD-9-CMHistory

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

ICD-9-CM
721.1 Cerv spondyl w myelopath
Approximate The match is approximate rather than exact.

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 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About M47.011Overview

Is M47.011 (Anterior spinal artery compression syndromes) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report anterior spinal artery compression syndromes, occipito-atlanto-axial region on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M47.011 group to?

When anterior spinal artery compression syndromes, occipito-atlanto-axial region is the principal diagnosis on an inpatient stay, it groups to MS-DRG 551, 552, with relative weights from 0.9613 to 1.6761 depending on complications. Higher weights mean higher Medicare reimbursement.

Is M47.011 a CC or MCC?

CMS lists M47.011 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 22 closely related codes in its exclusion list.

What is the ICD-9 equivalent of M47.011?

Under the General Equivalence Mappings, anterior spinal artery compression syndromes, occipito-atlanto-axial region converts to ICD-9-CM 721.1 (cerv spondyl w myelopath). The mapping is approximate, so confirm the match fits the documentation.