ICD-10-CM 2027
ICD-10 code for interstitial myositis
From the official ICD-10-CM alphabetic index entry “Myositis › interstitial”. Page updated September 29, 2026.
About coding interstitial myositis
The ICD-10-CM code for interstitial myositis is M60.10 (Interstitial myositis of unspecified site). The official index lists 10 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on M60.10.
Within M60.1, choose M60.10 (of unspecified site) only when documentation doesn't support a more specific option: shoulder (M60.11), upper arm (M60.12), forearm (M60.13), hand (M60.14), thigh (M60.15), lower leg (M60.16), ankle and foot (M60.17), other site (M60.18) and 1 more.
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 557 (Tendonitis, Myositis and Bursitis with MCC, relative weight 1.489) and DRG 558 (Tendonitis, Myositis and Bursitis without MCC, relative weight 0.8875), 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.
More specific interstitial myositis codes (official index)
- ankle M60.17 — Interstitial myositis, ankle and foot
- foot M60.17 — Interstitial myositis, ankle and foot
- forearm M60.13 — Interstitial myositis, forearm
- hand M60.14 — Interstitial myositis, hand
- lower leg M60.16 — Interstitial myositis, lower leg
- multiple sites M60.19 — Interstitial myositis, multiple sites
- shoulder region M60.11 — Interstitial myositis, shoulder
- specified site NEC M60.18 — Interstitial myositis, other site
- thigh M60.15 — Interstitial myositis, thigh
- upper arm M60.12 — Interstitial myositis, upper arm
Common questions about interstitial myositis ICD-10 codes
What is the ICD-10 code for interstitial myositis?
- M60.10 — Interstitial myositis of unspecified site. More specific codes apply when the documentation supports them: M60.17, M60.17, M60.13, M60.14 and others below.
What is the ICD-10 code for ankle interstitial myositis?
- M60.17 — Interstitial myositis, ankle and foot (header code; choose a more specific subcode).
What is the ICD-10 code for foot interstitial myositis?
- M60.17 — Interstitial myositis, ankle and foot (header code; choose a more specific subcode).
What is the ICD-10 code for forearm interstitial myositis?
- M60.13 — Interstitial myositis, forearm (header code; choose a more specific subcode).
What is the ICD-10 code for hand interstitial myositis?
- M60.14 — Interstitial myositis, hand (header code; choose a more specific subcode).
What is the ICD-10 code for lower leg interstitial myositis?
- M60.16 — Interstitial myositis, lower leg (header code; choose a more specific subcode).
What is the ICD-10 code for multiple sites interstitial myositis?
- M60.19 — Interstitial myositis, multiple sites.
Is M60.10 billable?
- Yes. M60.10 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can M60.10 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict M60.10 as a principal diagnosis.
Is M60.10 a CC or MCC?
- No. M60.10 is neither a CC nor an MCC under MS-DRG v44.0.