2026 ICD-10-CM Diagnosis Code M99.10Subluxation complex (vertebral) of head region

ICD-10-CM Codes›M00–M99›M99›M99

ICD-10-CM M99.10
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M99.10 is a billable ICD-10-CM diagnosis code for subluxation complex (vertebral) of head 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, 963 through 965. 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 238 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Biomechanical lesions.

Code Identity

ICD-10-CM Code
M99.10
Billable Status
Yes — Valid for Submission
Code Describes
Subluxation complex (vertebral) of head region
Short Description
Subluxation complex (vertebral) of head region
Same as the full description in the CMS dataset.
Parent Code
M99.1
Subluxation complex (vertebral)

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM99Biomechanical lesions, not elsewhere classified
CategoryM99Biomechanical lesions, not elsewhere classified
This CodeM99.10Subluxation complex (vertebral) of head 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 MUS012
Biomechanical lesions
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Dislocations

Dislocations are joint injuries that force the ends of your bones out of position. The cause is often a fall or a blow, sometimes from playing a contact sport. You can dislocate your ankles, knees, shoulders, hips, elbows and jaw. You can also dislocate your finger and toe joints.

Read the full article at MedlinePlus

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

Convert M99.10 to ICD-9-CMHistory

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

ICD-9-CM
839.00 Disloc cerv vert NOS-cl
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 M99.10Overview

What is the ICD-10 code for subluxation complex (vertebral) of head region?

The ICD-10-CM code for subluxation complex (vertebral) of head region is M99.10 (sometimes written as M9910). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is M99.10 (Subluxation complex (vertebral)) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report subluxation complex (vertebral) of head region on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M99.10 group to?

When subluxation complex (vertebral) of head region is the principal diagnosis on an inpatient stay, it groups to MS-DRG 551, 552, 963, 964, 965, with relative weights from 0.9405 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

Is M99.10 a CC or MCC?

CMS lists M99.10 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 238 closely related codes in its exclusion list.

What is the ICD-9 equivalent of M99.10?

Under the General Equivalence Mappings, subluxation complex (vertebral) of head region converts to ICD-9-CM 839.00 (disloc cerv vert NOS-cl). The mapping is approximate, so confirm the match fits the documentation.