N10 — Acute pyelonephritis
Is N10 billable?
Yes — N10 is billable for FY2027. N10 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. N10 may be submitted for encounters from October 1, 2026 through September 30, 2027.
N10 at a glance
| Code | N10 |
|---|---|
| Description | Acute pyelonephritis |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does N10 group to?
N10 sits in MDC 11 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 689Kidney and Urinary Tract Infections with MCCmedical
- 690Kidney and Urinary Tract Infections without MCCmedical
As a secondary diagnosis, N10 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG. It also carries Hospital-Acquired Condition category 06.
How is N10 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to N10. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Nephrosis, nephrotic › hemoglobin (Epstein's) (syndrome) (congenital)
- Nephrosis, nephrotic › myoglobin (Epstein's) (syndrome) (congenital)
- Pyelitis › acute (congenital) (uremic)
- Pyelonephritis › acute
- Nephritis, nephritic › tubulo-interstitial › acute (albuminuric) (azotemic) (congenital) (disseminated) (epithelial) (familial) (focal) (granulomatous) (hemorrhagic) (infantile) (nonsuppurative, excretory) (uremic)
Use additional code
Report an additional code alongside N10 to fully describe the condition. N10 is sequenced first.
- code (B95-B97), to identify infectious agent.
Inclusion terms
Alternative wording in documentation that is classified to N10.
- Acute infectious interstitial nephritis
- Acute pyelitis
- Acute tubulo-interstitial nephritis
- Hemoglobin nephrosis
- Myoglobin nephrosis
Excludes1 — never code together — inherited from N10-N16
The conditions below can never be reported together with N10 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- pyeloureteritis cystica (N28.85)
Excludes2 — not included here — inherited from Chapter 14
The conditions below are not part of N10, but a patient may have both at the same time. When documentation supports it, N10 and the excluded code may both be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
How long has N10 existed?
N10 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
- FY2018Acute tubulo-interstitial nephritisAcute pyelonephritis
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.
Which codes are confused with N10?
ICD-10-CM declares these codes mutually exclusive with N10 — exactly one of each pair can be correct for a given encounter.