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ICD-10-CM 2027 diagnosis code

N16Renal tubulo-interstitial disorders in diseases classified elsewhere

✓ Billable / specificManifestation — not principal

N16 is a valid, billable ICD-10-CM code for renal tubulo-interstitial disorders in diseases classified elsewhere. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Renal tubulo-interstitial disord in diseases classd elswhr

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About N16

N16 is the ICD-10-CM diagnosis code for renal tubulo-interstitial disorders in diseases classified elsewhere. It belongs to block N10-N16 (renal tubulo-interstitial diseases) and chapter 14 (diseases of the genitourinary system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Don't report N16 together with the conditions in its Excludes1 note: 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) and 6 more.

Code first underlying disease, such as: brucellosis (A23.0-A23.9), cryoglobulinemia (D89.1), glycogen storage disease (E74.0-), leukemia (C91-C95) and 4 more.

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 698 (Other Kidney and Urinary Tract Diagnoses with MCC, relative weight 1.6398), DRG 699 (Other Kidney and Urinary Tract Diagnoses with CC, relative weight 1.0003) and DRG 700 (Other Kidney and Urinary Tract Diagnoses without CC/MCC, relative weight 0.6741), in MDC 11 (Diseases and Disorders of the Kidney and Urinary Tract), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is a manifestation code, so it describes the effect of an underlying disease and can't be the principal diagnosis. Code the underlying condition first.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 583.81 (nephritis and nephropathy, not specified as acute or chronic, in diseases classified elsewhere) and 590.81 (Pyelitis or pyelonephritis in diseases classified elsewhere).

Coding notes

Applicable toConditions and synonyms classified to this code
  • Pyelonephritis
  • Tubulo-interstitial nephritis
Excludes1Not coded here — never report together with this 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 firstSequence the underlying condition first

Notes that apply from higher levels

Instructions written at a parent level also apply to N16.

Broader instructions also apply from N10-N16 Renal tubulo-interstitial diseases and Chapter 14: Diseases of the genitourinary system.

Codes whose notes reference N16

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 583.81Nephritis and nephropathy, not specified as acute or chronic, in diseases classified elsewhereapproximate
  • 590.81Pyelitis or pyelonephritis in diseases classified elsewhereapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about N16

Is N16 billable?

Yes. N16 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can N16 be used as a principal diagnosis?

No. It is a manifestation code, so it describes the effect of an underlying disease and can't be the principal diagnosis. Code the underlying condition first.

Is N16 a CC or MCC?

No. N16 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does N16 group to?

N16 is used in the MS-DRG v44.0 logic for MS-DRG 698 (Other Kidney and Urinary Tract Diagnoses with MCC), MS-DRG 699 (Other Kidney and Urinary Tract Diagnoses with CC) and MS-DRG 700 (Other Kidney and Urinary Tract Diagnoses without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for N16?

The CMS General Equivalence Mappings map N16 to ICD-9-CM 583.81 and 590.81.