2027 ICD-10-CM Diagnosis Code N10Acute pyelonephritis
ICD-10-CM Codes›N00–N99›N10-N16›N10
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Not Chronic
N10 is a billable ICD-10-CM diagnosis code for acute pyelonephritis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 689 through 690, 791, 793. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 279 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Urinary tract infections.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute bacterial tubulointerstitial nephritis
- Acute fungal tubulointerstitial nephritis
- Acute infectious tubulointerstitial nephritis
- Acute nephritis due to another disorder
- Acute on chronic tubulointerstitial nephritis
- Acute pyelitis
- Acute pyelitis with renal medullary necrosis
- Acute pyelitis without renal medullary necrosis
- Acute pyelonephritis
- Acute pyelonephritis caused by bacterium
- Acute pyelonephritis with medullary necrosis
- Acute pyelonephritis without medullary necrosis
- Acute tubulointerstitial nephritis
- Acute tubulointerstitial nephritis associated with systemic infection
- Acute tubulo-interstitial nephritis due to immunological disorder
- Acute viral tubulointerstitial nephritis
- Bacterial nephritis
- Emphysematous pyelitis
- Emphysematous pyelonephritis
- Focal pyelonephritis
- Fungal infection of kidney
- Idiopathic acute tubulointerstitial nephritis
- Pyelitis
- Pyelonephritis associated with another disorder
- Renal ocular syndrome
- Viral kidney infection
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to N10: its own notes plus those printed at block N10-N16 and Chapter 14. A note printed at a category, block or chapter applies to every code under it.
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Acute infectious interstitial nephritis
- Acute pyelitis
- Acute tubulo-interstitial nephritis
- Hemoglobin nephrosis
- Myoglobin nephrosis
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- pyeloureteritis cystica (N28.85)
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may 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)
Use Additional Code
Add a second code, after this one, to fully describe the condition.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name N10, its category, or a range that includes it.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Nephritis, nephritic (albuminuric) (azotemic) (congenital) (disseminated) (epithelial) (familial) (focal) (granulomatous) (hemorrhagic) (infantile) (nonsuppurative, excretory) (uremic) N05.9
Pyelitis (congenital) (uremic) See Also: Pyelonephritis;
acute N10
Pyelonephritis See Also: Nephritis, tubulo-interstitial;
acute N10
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Acute Pyelonephritis
sudden onset pyelonephritis.
Patient EducationClinical
Kidney Diseases
You have two kidneys, each about the size of your fist. They are near the middle of your back, just below the rib cage. Inside each kidney there are about a million tiny structures called nephrons. They filter your blood. They remove wastes and extra water, which become urine. The urine flows through tubes called ureters.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert N10 to ICD-9-CMHistory
Code HistoryHistory
Questions About N10Overview
What is the ICD-10 code for acute pyelonephritis?
The ICD-10-CM code for acute pyelonephritis is N10. It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is N10 (Acute pyelonephritis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report acute pyelonephritis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does N10 group to?
When acute pyelonephritis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 793, 791, 689, 690, with relative weights from 0.8008 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.
Is N10 a CC or MCC?
CMS lists N10 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 279 closely related codes in its exclusion list.
Can N10 be reported with N28.85?
Not as a rule. The Excludes1 note at block N10-N16, which applies to N10, lists "pyeloureteritis cystica (N28.85)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
