ICD-10-CM 2027
ICD-10 code for kidney infection
From the official ICD-10-CM alphabetic index entry “Infection, infected, infective (opportunistic) › kidney (cortex) (hematogenous)”. Page updated September 29, 2026.
About coding kidney infection
The ICD-10-CM code for kidney infection is N15.9 (Renal tubulo-interstitial disease, unspecified). The official index lists 6 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on N15.9.
Within N15, choose N15.9 (Renal tubulo-interstitial disease, unspecified) only when documentation doesn't support a more specific option: Balkan nephropathy (N15.0), renal and perinephric abscess (N15.1) and other specified renal tubulo-interstitial diseases (N15.8).
Don't report N15.9 together with the conditions in its Excludes1 note: urinary tract infection NOS (N39.0).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
More specific kidney infection codes (official index)
- with calculus N20.0 — Calculus of kidney
- with hydronephrosis N13.6 — Pyonephrosis
- following ectopic gestation O08.83 — Urinary tract infection following an ectopic and molar pregnancy
- pelvis and ureter (cystic) N28.85 — Pyeloureteritis cystica
- puerperal (postpartum) O86.21 — Infection of kidney following delivery
- specified NEC N15.8 — Other specified renal tubulo-interstitial diseases
Don't confuse with (Excludes1 for N15.9)
- urinary tract infection NOS (N39.0)
Common questions about kidney infection ICD-10 codes
What is the ICD-10 code for kidney infection?
- N15.9 — Renal tubulo-interstitial disease, unspecified. More specific codes apply when the documentation supports them: N20.0, N13.6, O08.83, N28.85 and others below.
What is the ICD-10 code for pelvis and ureter kidney infection?
- N28.85 — Pyeloureteritis cystica.
What is the ICD-10 code for puerperal kidney infection?
- O86.21 — Infection of kidney following delivery.
Is N15.9 billable?
- Yes. N15.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can N15.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict N15.9 as a principal diagnosis.
Is N15.9 a CC or MCC?
- No. N15.9 is neither a CC nor an MCC under MS-DRG v44.0.