E13- vs N16
E13 and N16 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.
Other specified diabetes mellitus
- Chapter 4
- Endocrine, nutritional and metabolic diseases
- Section
- E08-E13
- diabetes mellitus due to genetic defects of beta-cell function
- diabetes mellitus due to genetic defects in insulin action
- postpancreatectomy diabetes mellitus
- postprocedural diabetes mellitus
- secondary diabetes mellitus NEC
Renal tubulo-interstitial disorders in diseases classified elsewhere
- Chapter 14
- Diseases of the genitourinary system
- Section
- N10-N16
- Pyelonephritis
- Tubulo-interstitial nephritis
- Disorder › tubulo-interstitial › brucellosis
- Disorder › tubulo-interstitial › glycogen storage disease
- Disorder › tubulo-interstitial › leukemia NEC
- Disorder › tubulo-interstitial › lymphoma NEC
- Disorder › tubulo-interstitial › mixed cryoglobulinemia
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