2026 ICD-10-CM Diagnosis Code M12.359Palindromic rheumatism, unspecified hip

ICD-10-CM Codes›M00–M99›M05-M14›M12

ICD-10-CM M12.359
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M12.359 is a billable ICD-10-CM diagnosis code for palindromic rheumatism, unspecified hip. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 553 through 554. Coders also document this condition as palindromic rheumatism of pelvic region and thigh. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified joint disorders.

Code Identity

ICD-10-CM Code
M12.359
Billable Status
Yes — Valid for Submission
Code Describes
Palindromic rheumatism, unspecified hip
Short Description
Palindromic rheumatism, unspecified hip
Same as the full description in the CMS dataset.
Parent Code
M12.35
Palindromic rheumatism, hip

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM05-M14Inflammatory polyarthropathies
CategoryM12Other and unspecified arthropathy
This CodeM12.359Palindromic rheumatism, unspecified hip

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Palindromic rheumatism of pelvic region and thigh

Clinical ClassificationClinical

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

CCSR MUS007
Other specified joint disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a form of arthritis that causes pain, swelling, and stiffness in your joints. RA is an autoimmune disease. Although it is most common in the wrist and fingers, this disease can cause your immune system to attack any joint tissue. The inflammation (swelling) that comes with RA can also affect other body parts.

The full article covers:

  • What is rheumatoid arthritis?
  • Who is more likely to get rheumatoid arthritis?
  • What causes rheumatoid arthritis?
  • What are the symptoms of rheumatoid arthritis?
  • How is rheumatoid arthritis diagnosed?
  • What are the treatments for rheumatoid arthritis?

Read the full article at MedlinePlus

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

Convert M12.359 to ICD-9-CMHistory

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

ICD-9-CM
719.35 Palindrom rheum-pelvis
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 M12.359Overview

Is M12.359 (Palindromic rheumatism, hip) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report palindromic rheumatism, unspecified hip on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M12.359 group to?

When palindromic rheumatism, unspecified hip is the principal diagnosis on an inpatient stay, it groups to MS-DRG 553, 554, with relative weights from 0.8301 to 1.2963 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M12.359?

Under the General Equivalence Mappings, palindromic rheumatism, unspecified hip converts to ICD-9-CM 719.35 (palindrom rheum-pelvis). 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.