Excludes1 pair
N13.2 vs N20-
N13.2 and N20 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 N20
that with hydronephrosis (N13.2)
N13.2
Hydronephrosis with renal and ureteral calculous obstruction
Billable
- Chapter 14
- Diseases of the genitourinary system
- Section
- N10-N16
Indexed under
- Calculus, calculi, calculous › ureter › with hydronephrosis
- Calculus, calculi, calculous › urinary › with hydronephrosis
- Calculus, calculi, calculous › kidney › with calculus, ureter › with hydronephrosis
- Calculus, calculi, calculous › kidney › congenital › with hydronephrosis
- Calculus, calculi, calculous › ureter › with calculus, kidney › with hydronephrosis
N20
Calculus of kidney and ureter
Not billable
- Chapter 14
- Diseases of the genitourinary system
- Section
- N20-N23
Use when the record says
- Calculous pyelonephritis
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