M61.00 ICD-10-CM Code: Myositis ossificans traumatica, unspecified site

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for M61.00 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on M61.00 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for M61.00

MedCoder structured workflow — derived from this code’s own official record

Before you code M61.00

1. Unspecified does not mean incorrect. When the record gives no greater specificity, M61.00 may be the appropriate code. Check the record for detail that supports a more specific sibling. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

   ReviewM61.01, M61.02, M61.03, M61.04, M61.05, M61.06, M61.07, M61.08

   See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

2. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with M61.00. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

   See the official tabular notes

Choose the right path

1. Does the record document the detail a more specific sibling code needs?
   Yes → Review the specific siblings in this subcategory.
   No → Continue — M61.00 is appropriate when the documentation goes no further.

   ReviewM61.01, M61.02, M61.03, M61.04, M61.05, M61.06, M61.07, M61.08

2. Does the documentation support a condition named in M61.00’s Excludes1 note?
   Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
   No → Continue.

   ReviewM33, E85, M30.0, M05.32, M34, M35.03

Consider M61.00. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement

Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).

Any detail beyond this code’s title

What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

• Excludes1 — check before selecting M61.00(7 notes)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with M61.00: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareM33, E85, M30.0, M05.32, M34, M35.03

  See the official tabular notes · Guidelines I.A.12.a

• Excludes2 — not part of M61.00(1 note)

  Coding workflow: The conditions named in this note are not included in M61.00. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  See the official tabular notes · Guidelines I.A.12.b

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Indexed Clinical Terms (1)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

• Myositis, ossificans or ossifying (circumscripta), traumatica

Don’t confuse M61.00 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of M61.00 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• M33— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of dermatopolymyositis moves the case to M33; the two are not reported together unless documented as unrelated.

  Full comparison: M61.00 vs M33 →

• E85— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of myopathy in amyloidosis moves the case to E85; the two are not reported together unless documented as unrelated.

  Full comparison: M61.00 vs E85 →

• M30.0— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of myopathy in polyarteritis nodosa moves the case to M30.0; the two are not reported together unless documented as unrelated.

  Full comparison: M61.00 vs M30.0 →

• M05.32— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of myopathy in rheumatoid arthritis moves the case to M05.32; the two are not reported together unless documented as unrelated.

  Full comparison: M61.00 vs M05.32 →

• M34— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of myopathy in scleroderma moves the case to M34; the two are not reported together unless documented as unrelated.

  Full comparison: M61.00 vs M34 →

• M35.03— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of myopathy in Sjögren's syndrome moves the case to M35.03; the two are not reported together unless documented as unrelated.

  Full comparison: M61.00 vs M35.03 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Verify Before Coding

• No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 2 MS-DRGs: DRG 557 (MDC 08), DRG 558 (MDC 08).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):MUS026 — Muscle disorders (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Muscle disorders).

+398 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Myositis”; these codes share that main term but sit in a different category of the Tabular List.

M60.12 — Interstitial myositis, upper arm (interstitial, upper arm), M60.13 — Interstitial myositis, forearm (interstitial, forearm), M60.14 — Interstitial myositis, hand (interstitial, hand), M60.15 — Interstitial myositis, thigh (interstitial, thigh), M60.16 — Interstitial myositis, lower leg (interstitial, lower leg), M60.17 — Interstitial myositis, ankle and foot (interstitial, foot), M60.18 — Interstitial myositis, other site (interstitial, specified site NEC), M60.19 — Interstitial myositis, multiple sites (interstitial, multiple sites), M60.80 — Other myositis, unspecified site (specified type NEC), M60.81 — Other myositis shoulder (specified type NEC, shoulder region), M60.82 — Other myositis, upper arm (specified type NEC, upper arm), M60.83 — Other myositis, forearm (specified type NEC, forearm), M60.84 — Other myositis, hand (specified type NEC, hand), M60.85 — Other myositis, thigh (specified type NEC, thigh), M60.86 — Other myositis, lower leg (specified type NEC, lower leg), M60.87 — Other myositis, ankle and foot (specified type NEC, foot), M60.88 — Other myositis, other site (specified type NEC, specified site NEC), M60.89 — Other myositis, multiple sites (specified type NEC, multiple sites), M60.9 — Myositis, unspecified, T79.6 — Traumatic ischemia of muscle (fibrosa or fibrous, Volkmann's), +32 more

Contextual Map

Every relationship of M61.00 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Hierarchy

• M00-M99 — Chapter 13: Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) (M00-M99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M60-M63 — Disorders of muscles[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Clinical classification (CCSR)

• MUS026 — Muscle disorders[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

MS-DRG Grouper

• DRG 557 — TENDONITIS, MYOSITIS AND BURSITIS WITH MCC[MS-DRG]: “TENDONITIS, MYOSITIS AND BURSITIS WITH MCC (MDC 08)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 558 — TENDONITIS, MYOSITIS AND BURSITIS WITHOUT MCC[MS-DRG]: “TENDONITIS, MYOSITIS AND BURSITIS WITHOUT MCC (MDC 08)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 08 — Diseases and Disorders of the Musculoskeletal System and Connective Tissue[MDC crossing]: “Diseases and Disorders of the Musculoskeletal System and Connective Tissue — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 18,508 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

• Myositis, ossificans or ossifying (circumscripta), traumatica[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (40)

• M61 — Calcification and ossification of muscle[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M61.0 — Myositis ossificans traumatica[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M61.01 — Myositis ossificans traumatica, shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M61.011 — Myositis ossificans traumatica, right shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M61.012 — Myositis ossificans traumatica, left shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M61.019 — Myositis ossificans traumatica, unspecified shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M61.02 — Myositis ossificans traumatica, upper arm[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M61.021 — Myositis ossificans traumatica, right upper arm[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 32 more

Change history

• FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data

CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page

Inpatient payment groups Official source data

CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page

Change history and date-of-service validity Official source data

CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page

Comparisons, relationships and the contextual map MedCoder structured relationship

Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears

Summary and FAQ answers MedCoder explanation

Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Nearest Codes in This Family

Official ICD-10-CM classifications closest to M61.00 in its code family, with their registry titles.

• M61 — Calcification and ossification of muscle
• M61.0 — Myositis ossificans traumatica
• M61.01 — Myositis ossificans traumatica, shoulder
• M61.011 — Myositis ossificans traumatica, right shoulder
• M61.012 — Myositis ossificans traumatica, left shoulder
• M61.019 — Myositis ossificans traumatica, unspecified shoulder
• M61.02 — Myositis ossificans traumatica, upper arm
• M61.021 — Myositis ossificans traumatica, right upper arm
• M61.022 — Myositis ossificans traumatica, left upper arm
• M61.029 — Myositis ossificans traumatica, unspecified upper arm

View all codes in the M61 family