Excludes1 pair
M48.1- vs M85.8-
M48.1 and M85.8 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 M85.8
diffuse idiopathic skeletal hyperostosis [DISH] (M48.1)
M48.1
Ankylosing hyperostosis [Forestier]
Not billable
- Chapter 13
- Diseases of the musculoskeletal system and connective tissue
- Section
- M45-M49
Use when the record says
- Diffuse idiopathic skeletal hyperostosis [DISH]
M85.8
Other specified disorders of bone density and structure
Not billable
- Chapter 13
- Diseases of the musculoskeletal system and connective tissue
- Section
- M80-M85
Use when the record says
- Hyperostosis of bones, except skull
- Osteosclerosis, acquired
Indexed under
- Osteopenia
- Borderline › osteopenia
- Osteopenia › borderline
- Osteosclerosis › acquired
- Disorder › bone › density and structure › specified type NEC
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