10ICD Code Hub

N11.1

Billable code

Chronic obstructive pyelonephritis

The ICD-10 code for chronic obstructive pyelonephritis is N11.1.

Clinical notes

Excludes1 (not coded here)

An Excludes1 note is a pure exclusion: the excluded condition and this code should never be reported together, because the two conditions cannot occur at the same time (e.g. a congenital form vs. an acquired form of the same disease).

  • calculous pyelonephritis (N20.9)
  • obstructive uropathy (N13.-)

Also known as

Alternate wording, synonyms, or specific conditions that fall under this code, listed to help confirm you've picked the right one.

  • 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

Documentation support

General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.

Related codes in this category

ICD-9-CM equivalent

Informational only — GEM mappings are approximate, not guaranteed one-to-one equivalents. Verify before use in billing.

View full ICD-10 → ICD-9 crosswalk →

Associated MS-DRGs

N11.1 can serve as the principal diagnosis for these Medicare Severity Diagnosis-Related Groups.

Informational only — actual DRG assignment also depends on procedures, complications/comorbidities (CC/MCC), discharge status, and payer-specific rules not reflected here.