ICD-10-CM Code N12

Tubulo-interstitial nephritis, not specified as acute or chronic

Version 2020 Billable Code

Valid for Submission

N12 is a billable code used to specify a medical diagnosis of tubulo-interstitial nephritis, not specified as acute or chronic. The code is valid for the year 2020 for the submission of HIPAA-covered transactions. The ICD-10-CM code N12 might also be used to specify conditions or terms like acute interstitial nephritis, anti-glomerular basement membrane tubulointerstitial nephritis, diffuse pyelonephritis, familial interstitial nephritis, granulomatous interstitial nephritis, idiopathic granulomatous interstitial nephropathy, etc

Short Description:Tubulo-interstitial nephritis, not spcf as acute or chronic
Long Description:Tubulo-interstitial nephritis, not specified as acute or chronic

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code N12:

Inclusion Terms

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

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

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code N12 are found in the index:


The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Acute interstitial nephritis
  • Anti-glomerular basement membrane tubulointerstitial nephritis
  • Diffuse pyelonephritis
  • Familial interstitial nephritis
  • Granulomatous interstitial nephritis
  • Idiopathic granulomatous interstitial nephropathy
  • Idiopathic interstitial nephritis
  • Immunologic mediated TIN
  • Interstitial nephritis
  • Mycoplasmal pyelonephritis
  • Primary tubulointerstitial nephritis
  • Pyelitis
  • Pyelonephritis
  • Renal tubulo-interstitial disorders in blood diseases and disorders involving the immune mechanism
  • Secondary tubulointerstitial nephritis
  • Subacute pyelonephritis
  • Tubulointerstitial nephritis
  • Tubulointerstitial nephritis with uveitis syndrome

Diagnostic Related Groups

The ICD-10 code N12 is grouped in the following groups for version MS-DRG V37.0 What are Diagnostic Related Groups?
The Diagnostic Related Groups (DRGs) are a patient classification scheme which provides a means of relating the type of patients a hospital treats. The DRGs divides all possible principal diagnoses into mutually exclusive principal diagnosis areas referred to as Major Diagnostic Categories (MDC).
applicable from 10/01/2019 through 09/30/2020.


Convert N12 to ICD-9

  • 590.80 - Pyelonephritis NOS (Approximate Flag)

Code Classification

  • Diseases of the genitourinary system (N00–N99)
    • Renal tubulo-interstitial diseases (N10-N16)
      • Tubulo-interstitial nephritis, not spcf as acute or chronic (N12)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020

Information for Patients

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. It goes to your bladder, which stores the urine until you go to the bathroom.

Most kidney diseases attack the nephrons. This damage may leave kidneys unable to remove wastes. Causes can include genetic problems, injuries, or medicines. You have a higher risk of kidney disease if you have diabetes, high blood pressure, or a close family member with kidney disease. Chronic kidney disease damages the nephrons slowly over several years. Other kidney problems include

  • Cancer
  • Cysts
  • Stones
  • Infections

Your doctor can do blood and urine tests to check if you have kidney disease. If your kidneys fail, you will need dialysis or a kidney transplant.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

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