2026 ICD-10-CM Diagnosis Code M43.8X4Other specified deforming dorsopathies, thoracic region

ICD-10-CM Codes›M00–M99›M40-M43›M43

ICD-10-CM M43.8X4
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M43.8X4 is a billable ICD-10-CM diagnosis code for other specified deforming dorsopathies, 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 rotational deformity of spine. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Spondylopathies/spondyloarthropathy (including infective).

Code Identity

ICD-10-CM Code
M43.8X4
Billable Status
Yes — Valid for Submission
Code Describes
Other specified deforming dorsopathies, thoracic region
Short Description
Other specified deforming dorsopathies, thoracic region
Same as the full description in the CMS dataset.
Parent Code
M43.8X
Other specified deforming dorsopathies

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM40-M43Deforming dorsopathies
CategoryM43Other deforming dorsopathies
This CodeM43.8X4Other specified deforming dorsopathies, thoracic region

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Rotational deformity of spine
  • Rotational deformity of thoracic spine
  • Rotational deformity of trunk

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

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 M43.8X4 to ICD-9-CMHistory

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

ICD-9-CM
737.8 Curvature of spine NEC
Approximate The match is approximate rather than exact.
ICD-9-CM
737.9 Curvature of spine 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 M43.8X4Overview

Is M43.8X4 (Other specified deforming dorsopathies) a billable code?

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

What MS-DRG does M43.8X4 group to?

When other specified deforming dorsopathies, 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 M43.8X4?

Under the General Equivalence Mappings, other specified deforming dorsopathies, thoracic region converts to ICD-9-CM 737.8 (curvature of spine NEC) and 737.9 (curvature of spine NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.