Excludes1 pair
M06.4 vs M13.0
M06.4 and M13.0 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.
The official note, declared on M06.4
polyarthritis NOS (M13.0)
M06.4
Inflammatory polyarthropathy
Billable
- Chapter 13
- Diseases of the musculoskeletal system and connective tissue
- Section
- M05-M14
Indexed under
- Polyarthritis, polyarthropathy › inflammatory
M13.0
Polyarthritis, unspecified
BillableUnspecified
- Chapter 13
- Diseases of the musculoskeletal system and connective tissue
- Section
- M05-M14
Indexed under
- Polyarthritis, polyarthropathy
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027