Tubulo-interstitial nephritis, not specified as acute or chronic (N12) ICD-10-CM
The N12 code range covers tubulo-interstitial nephritis, not specified as acute or chronic with 1 ICD-10-CM diagnosis codes. 1 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
- Interstitial nephritis NOS
- Pyelitis NOS
- Pyelonephritis NOS
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
- calculous pyelonephritis N20.9
Codes in the N12 Range 1 codes · 1 billable
- N12 Tubulo-interstitial nephritis, not specified as acute or chronic
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the N12 range.
Emphysematous Pyelonephritis
Acute often necrotizing pyelonephritis characterized by accumulation of gas within and around renal parenchyma. Emphysematous pyelonephritis is typically associated with bacterial infection in DIABETES MELLITUS and IMMUNOCOMPROMISED PATIENT.
Nephritis, Hereditary
A group of inherited conditions characterized initially by HEMATURIA and slowly progressing to RENAL INSUFFICIENCY. The most common form is the Alport syndrome (hereditary nephritis with HEARING LOSS) which is caused by mutations in genes for TYPE IV COLLAGEN and defective GLOMERULAR BASEMENT MEMBRANE.
Pyelitis
Inflammation of the KIDNEY PELVIS and KIDNEY CALICES where urine is collected before discharge, but does not involve the renal parenchyma (the NEPHRONS) where urine is processed.
Pyelonephritis
Inflammation of the KIDNEY involving the renal parenchyma (the NEPHRONS); KIDNEY PELVIS; and KIDNEY CALICES. It is characterized by ABDOMINAL PAIN; FEVER; NAUSEA; VOMITING; and occasionally DIARRHEA.
Pyelonephritis, Xanthogranulomatous
A chronic inflammatory condition of the KIDNEY resulting in diffuse renal destruction, a grossly enlarged and nonfunctioning kidney associated with NEPHROLITHIASIS and KIDNEY STONES.
About the N12 Code Range
The ICD-10 code N12 is used to classify tubulo-interstitial nephritis when it is not specified as either acute or chronic. This code helps identify inflammation of the kidney's tubules and surrounding interstitial tissue without a clear time course.
Tubulo-interstitial nephritis, also known by many synonyms such as idiopathic granulomatous interstitial nephropathy, subacute pyelonephritis, or granulomatous tubulointerstitial nephritis, involves inflammation that affects the kidney tissue beyond just the glomeruli. The code N12 covers various related terms including primary tubulointerstitial nephritis, pyelitis, and immunologically mediated forms like tubulointerstitial nephritis with uveitis syndrome or anti-glomerular basement membrane disease. It is particularly relevant when the diagnosis does not specify whether the condition is acute or chronic. This specificity is critical for medical coders seeking the correct ICD-10 code for conditions presenting with diffuse kidney inflammation potentially linked with urinary tract infections or systemic immune responses.
Questions About This Page
How many billable codes are in the N12 range?
Of the 1 codes in this range, 1 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the N12 range classify?
The range classifies tubulo-interstitial nephritis, not specified as acute or chronic. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
