2026 ICD-10-CM Diagnosis Code M40.13Other secondary kyphosis, cervicothoracic region

ICD-10-CM Codes›M00–M99›M40-M43›M40

ICD-10-CM M40.13
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M40.13 is a billable ICD-10-CM diagnosis code for other secondary kyphosis, cervicothoracic 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. The code is not accepted as a principal diagnosis by the Medicare Code Editor. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Scoliosis and other postural dorsopathic deformities.

Code Identity

ICD-10-CM Code
M40.13
Billable Status
Yes — Valid for Submission
Code Describes
Other secondary kyphosis, cervicothoracic region
Short Description
Other secondary kyphosis, cervicothoracic region
Same as the full description in the CMS dataset.
Parent Code
M40.1
Other secondary kyphosis

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM40-M43Deforming dorsopathies
CategoryM40Kyphosis and lordosis
This CodeM40.13Other secondary kyphosis, cervicothoracic region

Code EditsBilling

Medicare Code Editor checks that affect claim validity for M40.13.

Unacceptable principal diagnosis
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

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 MUS022
Scoliosis and other postural dorsopathic deformities
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 M40.13 to ICD-9-CMHistory

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

ICD-9-CM
737.41 Kyphosis in oth dis
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 M40.13Overview

What is the ICD-10 code for other secondary kyphosis, cervicothoracic region?

The ICD-10-CM code for other secondary kyphosis, cervicothoracic region is M40.13 (sometimes written as M4013). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is M40.13 (Other secondary kyphosis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other secondary kyphosis, cervicothoracic region on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M40.13 group to?

On inpatient claims, other secondary kyphosis, cervicothoracic region maps to MS-DRG 551, 552, with relative weights from 0.9613 to 1.6761 depending on complications. Higher weights mean higher Medicare reimbursement.

Can M40.13 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because other secondary kyphosis, cervicothoracic region describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

What is the ICD-9 equivalent of M40.13?

Under the General Equivalence Mappings, other secondary kyphosis, cervicothoracic region converts to ICD-9-CM 737.41 (kyphosis in oth dis). The mapping is approximate, so confirm the match fits the documentation.