Excludes1 pair
N11.1 vs N20.9
N11.1 and N20.9 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 N11.1
calculous pyelonephritis (N20.9)
N11.1
Chronic obstructive pyelonephritis
Billable
- Chapter 14
- Diseases of the genitourinary system
- Section
- N10-N16
Use when the record says
- Pyelonephritis (chronic) associated with anomaly of pelviureteric junction
- Pyelonephritis (chronic) associated with anomaly of pyeloureteric junction
- Pyelonephritis (chronic) associated with crossing of vessel
- Pyelonephritis (chronic) associated with kinking of ureter
- Pyelonephritis (chronic) associated with obstruction of ureter
- Pyelonephritis (chronic) associated with stricture of pelviureteric junction
- Pyelonephritis (chronic) associated with stricture of ureter
Indexed under
- Pyelonephrosis (obstructive)
- Obstruction, obstructed, obstructive › pyelonephritis (chronic)
- Pyelonephritis › chronic › associated with ureteral obstruction or stricture
- Pyelonephritis › chronic › obstructive
- Pyelonephritis › in › obstruction
N20.9
Urinary calculus, unspecified
BillableUnspecified
- Chapter 14
- Diseases of the genitourinary system
- Section
- N20-N23
Indexed under
- Anuria › calculous (impacted) (recurrent)
- Calculus, calculi, calculous › anuria (impacted) (recurrent)
- Calculus, calculi, calculous › urinary (duct) (impacted) (passage) (tract)
- Stone › urinary (duct) (impacted) (passage)
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