M13.179 — Monoarthritis, not elsewhere classified, unspecified ankle and foot
Is M13.179 billable?
Yes, but M13.179 is an unspecified code. M13.179 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, M13.179 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting M13.179 — the more specific alternatives are listed below.
M13.179 at a glance
| Code | M13.179 |
|---|---|
| Description | Monoarthritis, not elsewhere classified, unspecified ankle and foot |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does M13.179 group to?
M13.179 sits in MDC 08 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 553Bone Diseases and Arthropathies with MCCmedical
- 554Bone Diseases and Arthropathies without MCCmedical
How is M13.179 listed in the Alphabetic Index?
The Alphabetic Index lists these routes under M13.17, the nearest indexed parent of M13.179. Use them to find the family, then select the specific code.
- Monoarthritis › ankle
- Monoarthritis › foot joint
Excludes1 — never code together — inherited from M13
The conditions below can never be reported together with M13.179 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Excludes2 — not included here — inherited from Chapter 13
The conditions below are not part of M13.179, but a patient may have both at the same time. When documentation supports it, M13.179 and the excluded code may both 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)
How long has M13.179 existed?
M13.179 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.