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ICD-10-CM 2027 diagnosis code

M05.451Rheumatoid myopathy with rheumatoid arthritis of right hip

✓ Billable / specificCC — complication/comorbidity

M05.451 is a valid, billable ICD-10-CM code for rheumatoid myopathy with rheumatoid arthritis of right hip. 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 M05.451

M05.451 is the ICD-10-CM diagnosis code for rheumatoid myopathy with rheumatoid arthritis of right hip. It belongs to category M05 (rheumatoid arthritis with rheumatoid factor), block M05-M14 (inflammatory polyarthropathies) 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 M05.45 (rheumatoid myopathy with rheumatoid arthritis of hip), M05.451 is specifically for rheumatoid myopathy with rheumatoid arthritis of right hip. Related codes cover left hip (M05.452) and unspecified hip (M05.459).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 545 (Connective Tissue Disorders with MCC, relative weight 2.3892), DRG 546 (Connective Tissue Disorders with CC, relative weight 1.1745) and DRG 547 (Connective Tissue Disorders without CC/MCC, relative weight 0.7526), 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 359.6 (symptomatic inflammatory myopathy in diseases classified elsewhere) and 714.0 (rheumatoid arthritis).

Notes that apply from higher levels

Instructions written at a parent level also apply to M05.451.

› From M05 Rheumatoid arthritis with rheumatoid factor
Excludes1
  • rheumatic fever (I00)
  • juvenile rheumatoid arthritis (M08.-)
  • rheumatoid arthritis of spine (M45.-)

Broader instructions also apply from 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.

ICD-9-CM equivalent

Converter →
  • 359.6Symptomatic inflammatory myopathy in diseases classified elsewhereapproximate, combination
  • 714.0Rheumatoid arthritisapproximate, combination

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 M05.451

Is M05.451 billable?

Yes. M05.451 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can M05.451 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict M05.451 as a principal diagnosis.

Is M05.451 a CC or MCC?

M05.451 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.

What DRG does M05.451 group to?

M05.451 is used in the MS-DRG v44.0 logic for MS-DRG 545 (Connective Tissue Disorders with MCC), MS-DRG 546 (Connective Tissue Disorders with CC) and MS-DRG 547 (Connective Tissue Disorders without CC/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 M05.451?

The CMS General Equivalence Mappings map M05.451 to ICD-9-CM 359.6 and 714.0.