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  2. ICD-10-CM Codes List
  3. N00–N99
  4. N10-N16
  5. Tubulo-interstitial nephritis, not specified as acute or chronic (N12)

Tubulo-interstitial nephritis, not specified as acute or chronic (N12)

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.

Instructional Notations

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

Clinical Terms

The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.

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.