All ICD10 Codes
N16Billable, valid for claims from October 1, 2026

Renal tubulo-interstitial disorders in diseases classified elsewhere

In Renal tubulo-interstitial diseases (N10-N16), chapter 14: Diseases of the Genitourinary System

  • N16 is billable and valid on claims for FY 2027. If the record has more detail, check the other codes under N10-N16 below.
  • As a secondary diagnosis it is not a CC or MCC, so it doesn't raise the MS-DRG payment.
  • Doesn't count toward a Medicare Advantage risk score (no HCC in V28).
  • AHRQ's Chronic Condition Indicator classes it as not chronic (an acute or short-term condition).
  • Can't be the principal diagnosis: code the underlying condition first. (Manifestation list)

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Instructional notes

Includes: conditions that are coded here

  • Pyelonephritis
  • Tubulo-interstitial nephritis

Excludes1: not coded here, use a different code

  • diphtheritic pyelonephritis and tubulo-interstitial nephritis (A36.84)
  • pyelonephritis and tubulo-interstitial nephritis in candidiasis (B37.49)
  • pyelonephritis and tubulo-interstitial nephritis in cystinosis (E72.04)
  • pyelonephritis and tubulo-interstitial nephritis in salmonella infection (A02.25)
  • pyelonephritis and tubulo-interstitial nephritis in sarcoidosis (D86.84)
  • pyelonephritis and tubulo-interstitial nephritis in Sjogren syndrome (M35.04)
  • pyelonephritis and tubulo-interstitial nephritis in systemic lupus erythematosus (M32.15)
  • pyelonephritis and tubulo-interstitial nephritis in toxoplasmosis (B58.83)
  • renal tubular degeneration in diabetes (E08-E13 with .29)
  • syphilitic pyelonephritis and tubulo-interstitial nephritis (A52.75)

Code first: code the underlying condition first, then this code

Also applies, from Renal tubulo-interstitial diseases (N10-N16)

These notes sit on N10-N16 and apply to every code under it, including N16.

Includes: conditions that are coded here

  • pyelonephritis

Excludes1: not coded here, use a different code

  • pyeloureteritis cystica (N28.85)

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Covers chronic kidney disease staging, CKD in kidney transplant patients, and sequencing CKD with related conditions such as diabetes and hypertension.

Read Section I.C.14 (page 62)

Other codes under N10-N16

Renal tubulo-interstitial diseases (N10-N16)

N16 MS-DRGs

As the principal diagnosis, N16 groups to MS-DRG 698, 699, or 700 (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

Related conditions

Grouped by AHRQ's Clinical Classifications Software Refined (CCSR), which sorts every diagnosis code into clinically meaningful categories.

N16 is in Nephritis; nephrosis; renal sclerosis (GEN001), with 130 codes. Others in it:

  • A36.84 Diphtheritic tubulo-interstitial nephropathy
  • A51.44 Secondary syphilitic nephritis
  • B26.83 Mumps nephritis
  • B52.0 Plasmodium malariae malaria with nephropathy
  • B58.83 Toxoplasma tubulo-interstitial nephropathy
  • E08.21 Diabetes mellitus due to underlying condition with diabetic nephropathy
  • E09.21 Drug or chemical induced diabetes mellitus with diabetic nephropathy
  • E10.21 Type 1 diabetes mellitus with diabetic nephropathy

Medicare coverage articles listing N16

These 4 Medicare billing and coding articles list N16 as a diagnosis that supports medical necessity for the services they cover. From the CMS Medicare Coverage Database; check your own contractor's article before billing.

Other codes that refer to N16

Notes on these codes point to N16.

  • N08 Excludes1: pyelonephritis in diseases classified elsewhere (N16)
  • N08 Excludes1: renal tubulo-interstitial disorders classified elsewhere (N16)

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

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.

Read more about kidney diseases on MedlinePlus

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.

ICD-9-CM equivalent

Legacy crosswalk from the CMS General Equivalence Mappings (last updated 2018).

  • 583.81 Nephritis and nephropathy, not specified as acute or chronic, in diseases classified elsewhere (approximate)
  • 590.81 Pyelitis or pyelonephritis in diseases classified elsewhere (approximate)
ICD-9 to ICD-10 converter