2026 ICD-10-CM Diagnosis Code M40Kyphosis and lordosis

ICD-10-CM Codes›M00–M99›M40-M43›M40

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

M40 is a non-billable ICD-10-CM category code for kyphosis and lordosis, so it cannot be submitted on claims. Use a more specific code from this category instead, such as M40.00, M40.03, M40.04, and M40.05.

Code Identity

ICD-10-CM Code
M40
Billable Status
No — Non-Billable Category
Code Describes
Kyphosis and lordosis
Chapter
M40-M43
Deforming dorsopathies

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM40-M43Deforming dorsopathies
CategoryM40Kyphosis and lordosis
This CodeM40Kyphosis and lordosis

Specific Coding for Kyphosis and lordosisOverview

Non-specific codes like M40 require more characters. Use one of these billable codes instead:

  • M40.0 for Postural kyphosis

  • Use M40.00 for Postural kyphosis, site unspecified

  • Use M40.03 for Postural kyphosis, cervicothoracic region

  • Use M40.04 for Postural kyphosis, thoracic region

  • Use M40.05 for Postural kyphosis, thoracolumbar region

  • M40.1 for Other secondary kyphosis

  • Use M40.10 for Other secondary kyphosis, site unspecified

  • Use M40.12 for Other secondary kyphosis, cervical region

  • Use M40.13 for Other secondary kyphosis, cervicothoracic region

  • Use M40.14 for Other secondary kyphosis, thoracic region

  • Use M40.15 for Other secondary kyphosis, thoracolumbar region

  • M40.2 for Other and unspecified kyphosis

  • M40.20 for Unspecified kyphosis

  • M40.29 for Other kyphosis

  • M40.3 for Flatback syndrome

  • Use M40.30 for Flatback syndrome, site unspecified

  • Use M40.35 for Flatback syndrome, thoracolumbar region

  • Use M40.36 for Flatback syndrome, lumbar region

  • Use M40.37 for Flatback syndrome, lumbosacral region

  • M40.4 for Postural lordosis

  • Use M40.40 for Postural lordosis, site unspecified

  • Use M40.45 for Postural lordosis, thoracolumbar region

  • Use M40.46 for Postural lordosis, lumbar region

  • Use M40.47 for Postural lordosis, lumbosacral region

  • M40.5 for Lordosis, unspecified

  • Use M40.50 for Lordosis, unspecified, site unspecified

  • Use M40.55 for Lordosis, unspecified, thoracolumbar region

  • Use M40.56 for Lordosis, unspecified, lumbar region

  • Use M40.57 for Lordosis, unspecified, lumbosacral region

Tabular List NotesGuidance

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

Code First

  • underlying disease

Type 1 Excludes

  • congenital kyphosis and lordosis Q76.4
  • kyphoscoliosis M41
  • postprocedural kyphosis and lordosis M96

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.

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 M40Overview

Is M40 (Kyphosis and lordosis) a billable code?

No. This is a category header that groups the codes for kyphosis and lordosis, and headers cannot be submitted on claims. Claims for kyphosis and lordosis need a more specific code from this category, such as M40.00, M40.03, and M40.04.