2027 ICD-10-CM Diagnosis Code M63.879Disorders of muscle in diseases classified elsewhere, unspecified ankle and foot
ICD-10-CM Codes›M00–M99›M60-M63›M63
- Billable — Valid for Submission
- Not Chronic
M63.879 is a billable ICD-10-CM diagnosis code for disorders of muscle in diseases classified elsewhere, unspecified ankle and foot. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 557 through 558. The code is a manifestation code that cannot be reported as the principal diagnosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Muscle disorders.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for M63.879.
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to M63.879: its own notes plus those printed at M63, block M60-M63, and Chapter 13. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- arthropathic psoriasis (L40.5-)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- compartment syndrome (traumatic) (T79.A-)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Code First
The underlying condition named in the note is sequenced before this code.
Notes
General instructions on how these codes are used.
- Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Muscle Disorders
Your muscles help you move and help your body work. Different types of muscles have different jobs. There are many problems that can affect muscles. Muscle disorders can cause weakness, pain or even paralysis.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert M63.879 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M63.879Overview
Is M63.879 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report disorders of muscle in diseases classified elsewhere, unspecified ankle and foot on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does M63.879 group to?
On inpatient claims, disorders of muscle in diseases classified elsewhere, unspecified ankle and foot maps to MS-DRG 557, 558, with relative weights from 0.8873 to 1.4883 depending on complications. Higher weights mean higher Medicare reimbursement.
Can M63.879 be a principal diagnosis?
No. This is a manifestation code: disorders of muscle in diseases classified elsewhere, unspecified ankle and foot describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.
Can M63.879 be reported with B69.81?
Not as a rule. The Excludes1 note at M63, which applies to M63.879, lists "myopathy in cysticercosis (B69.81)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
