K11.8 vs M35
K11.8 and M35 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on K11.8
Sjögren syndrome (M35.0-)
K11.8
Other diseases of salivary glands
Billable
- Chapter 11
- Diseases of the digestive system
- Section
- K00-K14
Use when the record says
- Benign lymphoepithelial lesion of salivary gland
- Mikulicz' disease
- Necrotizing sialometaplasia
- Sialectasia
- Stenosis of salivary duct
- Stricture of salivary duct
Indexed under
- Mikulicz' disease or syndrome
- Pneumoparotid
- Sialectasia
- Sialometaplasia, necrotizing
- Cyst › ranular (colloid) (mucous) (simple) (retention)
M35
Other systemic involvement of connective tissue
Not billable
- Chapter 13
- Diseases of the musculoskeletal system and connective tissue
- Section
- M30-M36
These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.
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