2026 ICD-10-CM Diagnosis Code M84.573SPathological fracture in neoplastic disease, unspecified ankle, sequela

ICD-10-CM Codes›M00–M99›M80-M85›M84

ICD-10-CM M84.573S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M84.573S is a billable ICD-10-CM diagnosis code for pathological fracture in neoplastic disease, unspecified ankle, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 559 through 561. Coders also document this condition as pathologic fracture of ankle at site of neoplasm. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pathological, stress and atypical fractures, sequela.

Code Identity

ICD-10-CM Code
M84.573S
Billable Status
Yes — Valid for Submission
Code Describes
Pathological fracture in neoplastic disease, unspecified ankle, sequela
Short Description
Path fracture in neoplastic disease, unsp ankle, sequela
Parent Code
M84.573
Pathological fracture in neoplastic disease, unspecified ankle

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM80-M85Disorders of bone density and structure
CategoryM84Disorder of continuity of bone
This CodeM84.573SPathological fracture in neoplastic disease, unspecified ankle, sequela

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Pathologic fracture of ankle at site of neoplasm
  • Pathological fracture of ankle

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MUS020
Pathological, stress and atypical fractures, sequela
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Ankle Injuries and Disorders

Your ankle bone and the ends of your two lower leg bones make up the ankle joint. Your ligaments, which connect bones to one another, stabilize and support it. Your muscles and tendons move it.

Read the full article at MedlinePlus

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

Convert M84.573S to ICD-9-CMHistory

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

ICD-9-CM
905.4 Late effect leg fx
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 M84.573SOverview

Is M84.573S a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report pathological fracture in neoplastic disease, unspecified ankle, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in M84.573S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the pathological fracture in neoplastic disease, unspecified ankle itself has resolved, not the original event.

What MS-DRG does M84.573S group to?

When pathological fracture in neoplastic disease, unspecified ankle, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 559, 560, 561, with relative weights from 0.8039 to 1.8649 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M84.573S?

Under the General Equivalence Mappings, pathological fracture in neoplastic disease, unspecified ankle, sequela converts to ICD-9-CM 905.4 (late effect leg fx). 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.