2026 ICD-10-CM Diagnosis Code M33.10Other dermatomyositis, organ involvement unspecified

ICD-10-CM Codes›M00–M99›M30-M36›M33

ICD-10-CM M33.10
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M33.10 is a billable ICD-10-CM diagnosis code for other dermatomyositis, organ involvement unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 545 through 547. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Systemic lupus erythematosus and connective tissue disorders.

Code Identity

ICD-10-CM Code
M33.10
Billable Status
Yes — Valid for Submission
Code Describes
Other dermatomyositis, organ involvement unspecified
Short Description
Other dermatomyositis, organ involvement unspecified
Same as the full description in the CMS dataset.
Parent Code
M33.1
Other dermatomyositis

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM30-M36Systemic connective tissue disorders
CategoryM33Dermatopolymyositis
This CodeM33.10Other dermatomyositis, organ involvement unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Adult onset dermatomyositis
  • Antisynthetase syndrome
  • Anti-synthetase syndrome due to dermatomyositis
  • Autoimmune inflammation of skeletal muscle
  • Calcinosis due to adult type dermatomyositis
  • Connective tissue disease overlap syndrome
  • Dermatitis of the newborn
  • Neonatal dermatomyositis
  • Overlap syndrome
  • Poikilodermatomyositis
  • Sclerodermatomyositis

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Dermatomucosomyositis
    • Dermatomyositis(acute) (chronic)
      • adult
    • Dermatomyositis(acute) (chronic)
      • specified NEC
    • Dermatopolymyositis
      • specified NEC
    • Poikilodermatomyositis

Clinical ClassificationClinical

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

CCSR MUS024
Systemic lupus erythematosus and connective tissue disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Exosome Component 10|Autoantigen PM-SCL|Autoantigen PM/Scl|EC 3.1.13.-|EXOSC10|P100 Polymyositis-Scleroderma Overlap Syndrome-Associated Autoantigen|PM/Scl-100|Polymyositis/Scleroderma Autoantigen 100 kDa|Polymyositis/Scleroderma Autoantigen 2

    exosome component 10 (885 aa, ~101 kda) is encoded by the human exosc10 gene. this protein plays a role in the maturation and degradation of rna.

  • Other Overlap Syndromes|Other overlap syndromes

    evidence of other overlap syndromes not specified elsewhere.

  • Overlap Syndrome

    an autoimmune, connective tissue disorder in which the patient exhibits features from two or more diseases. these typically include systemic sclerosis, dermatomyositis, polymyositis, rheumatoid arthritis, systemic lupus erythematosus, and sjogren syndrome; in pediatrics the respective pediatric entities are encountered.

  • Scleroderma Polymyositis Overlap Syndrome|Scleroderma Polymyositis

    a rare autoimmune disorder in which patients present with overlapping symptoms of systemic scleroderma and polymyositis or dermatomyositis.

  • Exosome Complex Component RRP45|AMPA RECEPTORS|Autoantigen PM/Scl 1|EXOSC9|Exosome Component 9|GLuRs|P75 Polymyositis-Scleroderma Autoantigen|P75 Polymyositis-Scleroderma Overlap Syndrome Associated Autoantigen|P75 Polymyositis-Scleroderma Overlap Syndrome-Associated Autoantigen|PM/Scl-75|Polymyositis/Scleroderma Autoantigen 1|Polymyositis/Scleroderma Autoantigen 75 kDa

    exosome complex component rrp45 (439 aa, ~49 kda) is encoded by the human exosc9 gene. this protein is involved in the regulation of the exoribonuclease activity of the exosome.

  • Exosome Component 10|Autoantigen PM-SCL|Autoantigen PM/Scl|EC 3.1.13.-|EXOSC10|EXOSC10|P100 POLYMYOSITIS-SCLERODERMA AUTOANTIGEN|P100 Polymyositis-Scleroderma Overlap Syndrome-Associated Autoantigen|PM/Scl 2|PM/Scl-100|PM/Scl-100|Polymyositis/Scleroderma Autoantigen 100 kDa|Polymyositis/Scleroderma Autoantigen 2|Polymyositis/Scleroderma Autoantigen 2

    exosome component 10 (885 aa, ~101 kda) is encoded by the human exosc10 gene. this protein plays a role in the maturation and degradation of rna.

Patient EducationClinical

Myositis

Myositis means inflammation of the muscles that you use to move your body. An injury, infection, or autoimmune disease can cause it. Two specific kinds are polymyositis and dermatomyositis. Polymyositis causes muscle weakness, usually in the muscles closest to the trunk of your body.

Read the full article at MedlinePlus

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

Convert M33.10 to ICD-9-CMHistory

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

ICD-9-CM
710.3 Dermatomyositis
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 M33.10Overview

Is M33.10 (Other dermatomyositis) a billable code?

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

What MS-DRG does M33.10 group to?

When other dermatomyositis, organ involvement unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 545, 546, 547, with relative weights from 0.8362 to 2.4817 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M33.10?

Under the General Equivalence Mappings, other dermatomyositis, organ involvement unspecified converts to ICD-9-CM 710.3 (dermatomyositis). 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.