N16 Renal tubulo-interstitial disorders in diseases classified elsewhere

Billable

Block: Renal tubulo-interstitial diseases (N10-N16)

Includes

  • Pyelonephritis
  • Tubulo-interstitial nephritis

Excludes 1 (cannot be coded together)

  • 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

  • underlying disease, such as:
  • brucellosis (A23.0-A23.9)
  • cryoglobulinemia (D89.1)
  • glycogen storage disease (E74.0-)
  • leukemia (C91-C95)
  • lymphoma (C81.0-C85.9, C96.0-C96.9)
  • multiple myeloma (C90.0-)
  • sepsis (A40.0-A41.9)
  • Wilson's disease (E83.01)
This category is a complete, billable diagnosis code.

No additional specificity is required — submit N16 directly on claims and documentation without a subcode extension.

Last reviewed: September 2026