Skip to content
Dx

ICD-10-CM 2027 diagnosis code

M24.673Ankylosis, unspecified ankle

✓ Billable / specific

M24.673 is a valid, billable ICD-10-CM code for ankylosis, unspecified ankle. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About M24.673

M24.673 is the ICD-10-CM diagnosis code for ankylosis, unspecified ankle. It belongs to category M24 (other specific joint derangements), block M20-M25 (other joint disorders) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within M24.67, choose M24.673 (unspecified ankle) only when documentation doesn't support a more specific option: right ankle (M24.671), left ankle (M24.672), right foot (M24.674), left foot (M24.675) and unspecified foot (M24.676).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 553 (Bone Diseases and Arthropathies with MCC, relative weight 1.2494) and DRG 554 (Bone Diseases and Arthropathies without MCC, relative weight 0.8331), in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 718.57 (ankylosis of joint, ankle and foot).

Notes that apply from higher levels

Instructions written at a parent level also apply to M24.673.

› From M24.6 Ankylosis of joint
Excludes1
  • stiffness of joint without ankylosis (M25.6-)
Excludes2
› From M24 Other specific joint derangements
Excludes1
  • current injury - see injury of joint by body region
Excludes2

Broader instructions also apply from M20-M25 Other joint disorders and Chapter 13: Diseases of the musculoskeletal system and connective tissue.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

MDC 08 · Diseases and Disorders of the Musculoskeletal System and Connective Tissue

ICD-9-CM equivalent

Converter →
  • 718.57Ankylosis of joint, ankle and footapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about M24.673

Is M24.673 billable?

Yes. M24.673 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can M24.673 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict M24.673 as a principal diagnosis.

Is M24.673 a CC or MCC?

No. M24.673 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does M24.673 group to?

M24.673 is used in the MS-DRG v44.0 logic for MS-DRG 553 (Bone Diseases and Arthropathies with MCC) and MS-DRG 554 (Bone Diseases and Arthropathies without MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for M24.673?

The CMS General Equivalence Mappings map M24.673 to ICD-9-CM 718.57.