M05.171 (Rheumatoid lung disease with rheumatoid arthritis of right ankle and foot) compared with M05.179 (Rheumatoid lung disease with rheumatoid arthritis of unspecified ankle and foot), from the official CMS tabular data. M05.171 and M05.179 code the same condition on opposite sides.
Same condition; these differ only in which side is documented.
These codes share a category and title and differ only in the side affected. The documentation decides which applies, and a bilateral code is reported only where the code set provides one.
Source: ICD-10-CM tabular list (laterality variant derived from the code title)
Same condition, opposite side. M05.171 and M05.179 name the same condition on opposite sides of the body.
Same category and title, differing only in which side is affected — the documentation decides which one applies, and a bilateral code is reported only where the code set provides one.
| M05.171Rheumatoid lung disease with rheumatoid arthritis of right ankle and foot | M05.179Rheumatoid lung disease with rheumatoid arthritis of unspecified ankle and foot | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) | M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) |
| Definition | Rheumatoid lung disease with rheumatoid arthritis of right ankle and foot is a billable ICD-10-CM diagnosis code (M05.171). | Rheumatoid lung disease with rheumatoid arthritis of unspecified ankle and foot is a billable ICD-10-CM diagnosis code (M05.179). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources