M00.879 — Arthritis due to other bacteria, unspecified ankle and foot
Is M00.879 billable?
Yes, but M00.879 will trip a Medicare edit. M00.879 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, CMS lists M00.879 under Medicare Code Editor edit 20, “Unspecified code” — meaning a code specifying laterality (right, left or bilateral) exists in the same family. On an inpatient claim this triggers the edit, because CMS holds that there are very limited circumstances in which laterality cannot be documented.
M00.879 at a glance
| Code | M00.879 |
|---|---|
| Description | Arthritis due to other bacteria, unspecified ankle and foot |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
What Medicare edits apply to M00.879?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name M00.879 directly.
A code specifying laterality (right, left or bilateral) exists in the same family. CMS holds that there are very limited circumstances in which laterality cannot be documented.
Which MS-DRGs does M00.879 group to?
M00.879 sits in MDC 08 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 548Septic Arthritis with MCCmedical
- 549Septic Arthritis with CCmedical
- 550Septic Arthritis without CC/MCCmedical
As a secondary diagnosis, M00.879 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is M00.879 listed in the Alphabetic Index?
The Alphabetic Index lists these routes under M00.87, the nearest indexed parent of M00.879. Use them to find the family, then select the specific code.
- Arthritis, arthritic › pyogenic or pyemic › bacterial NEC › ankle (acute) (chronic) (nonpyogenic) (subacute)
Use additional code — inherited from M00.8
Report an additional code alongside M00.879 to fully describe the condition. M00.879 is sequenced first.
- code (B96) to identify bacteria
Excludes2 — not included here — inherited from Chapter 13
The conditions below are not part of M00.879, but a patient may have both at the same time. When documentation supports it, M00.879 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)
Excludes2 — not included here — inherited from M00
The conditions below are not part of M00.879, but a patient may have both at the same time. When documentation supports it, M00.879 and the excluded code may both be reported.
- infection and inflammatory reaction due to internal joint prosthesis (T84.5-)
How long has M00.879 existed?
M00.879 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.