2026 ICD-10-CM Diagnosis Code M50.921Unspecified cervical disc disorder at C4-C5 level

ICD-10-CM Codes›M00–M99›M50-M54›M50

ICD-10-CM M50.921
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M50.921 is a billable ICD-10-CM diagnosis code for unspecified cervical disc disorder at C4-C5 level. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Spondylopathies/spondyloarthropathy (including infective).

Code Identity

ICD-10-CM Code
M50.921
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified cervical disc disorder at C4-C5 level
Short Description
Unspecified cervical disc disorder at C4-C5 level
Same as the full description in the CMS dataset.
Parent Code
M50.92
Cervical disc disorder, unspecified, mid-cervical region

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM50-M54Other dorsopathies
CategoryM50Cervical disc disorders
This CodeM50.921Unspecified cervical disc disorder at C4-C5 level

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Unspecified C4-C5 cervical disc disorder

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 M50.921 to ICD-9-CMHistory

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

ICD-9-CM
722.91 Disc dis NEC/NOS-cerv
Approximate The match is approximate rather than exact.

Code History & ChangesHistory

Replacement M50.921 replaces the following previously assigned code(s):

  • M50.92 - Cervical disc disorder, unspecified, mid-cervical region
FY 2019AddedAdded to the ICD-10-CM code setEffective October 1, 2018.
FY 2020–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About M50.921Overview

What is the ICD-10 code for unspecified cervical disc disorder at C4-C5 level?

The ICD-10-CM code for unspecified cervical disc disorder at C4-C5 level is M50.921 (sometimes written as M50921). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is M50.921 (Cervical disc disorder, unspecified, mid-cervical region) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified cervical disc disorder at C4-C5 level on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M50.921 group to?

When unspecified cervical disc disorder at C4-C5 level 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.

What is the ICD-9 equivalent of M50.921?

Under the General Equivalence Mappings, unspecified cervical disc disorder at C4-C5 level converts to ICD-9-CM 722.91 (disc dis NEC/NOS-cerv). The mapping is approximate, so confirm the match fits the documentation.