2026 ICD-10-CM Diagnosis Code M40.04Postural kyphosis, thoracic region

ICD-10-CM Codes›M00–M99›M40-M43›M40

ICD-10-CM M40.04
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M40.04 is a billable ICD-10-CM diagnosis code for postural kyphosis, thoracic region. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 456 through 458, 551 through 552. Coders also document this condition as kyphosis of thoracic spine. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Scoliosis and other postural dorsopathic deformities.

Code Identity

ICD-10-CM Code
M40.04
Billable Status
Yes — Valid for Submission
Code Describes
Postural kyphosis, thoracic region
Short Description
Postural kyphosis, thoracic region
Same as the full description in the CMS dataset.
Parent Code
M40.0
Postural kyphosis

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM40-M43Deforming dorsopathies
CategoryM40Kyphosis and lordosis
This CodeM40.04Postural kyphosis, thoracic region

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Kyphosis of thoracic spine
  • Postural kyphosis
  • Thoracic postural kyphosis

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

Spine Injuries and Disorders

Your backbone, or spine, is made up of 26 bone discs called vertebrae. The vertebrae protect your spinal cord and allow you to stand and bend. A number of problems can change the structure of the spine or damage the vertebrae and surrounding tissue. They include:

Read the full article at MedlinePlus

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

Convert M40.04 to ICD-9-CMHistory

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

ICD-9-CM
737.10 Kyphosis NOS
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 M40.04Overview

What is the ICD-10 code for postural kyphosis, thoracic region?

The ICD-10-CM code for postural kyphosis, thoracic region is M40.04 (sometimes written as M4004). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is M40.04 (Postural kyphosis) a billable code?

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

What MS-DRG does M40.04 group to?

When postural kyphosis, thoracic region is the principal diagnosis on an inpatient stay, it groups to MS-DRG 456, 457, 458, 551, 552, with relative weights from 0.9613 to 8.4034 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M40.04?

Under the General Equivalence Mappings, postural kyphosis, thoracic region converts to ICD-9-CM 737.10 (kyphosis NOS). The mapping is approximate, so confirm the match fits the documentation.