N11.9 Chronic tubulo-interstitial nephritis, unspecified

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applicable to

• Chronic interstitial nephritis NOS
• Chronic pyelitis NOS
• Chronic pyelonephritis NOS

Applies from N11 Chronic tubulo-interstitial nephritis

Includes

• chronic infectious interstitial nephritis
• chronic pyelitis
• chronic pyelonephritis

Use additional code

• code (B95-B97), to identify infectious agent.

MS-DRG index

Defines the logic of DRG(s) 689-690 in MDC 11.

Approximate ICD-9-CM (GEMs)

• 590.80 Pyelonephritis, unspecified (approximate)

Code annotations containing back-references to N11.9

Back-references to N11

• Type 1 Excludes: N03 Chronic nephritic syndrome ("chronic tubulo-interstitial nephritis (N11.-)")

Diagnosis Index entries for N11.9

• Nephritis, nephritic (albuminuric) (azotemic) (congenital) (disseminated) (epithelial) (familial) (focal) (granulomatous) (hemorrhagic) (infantile) (nonsuppurative, excretory) (uremic) › tubulo-interstitial (in) › chronic (infectious)
• Pyelitis (congenital) (uremic) › with › contracted kidney
• Pyelitis (congenital) (uremic) › chronic
• Pyelonephritis › with › contracted kidney
• Pyelonephritis › chronic
• Pyelonephrosis (obstructive) › chronic

Nearby codes

• N11 Chronic tubulo-interstitial nephritis
• N11.0 Nonobstructive reflux-associated chronic pyelonephritis
• N11.1 Chronic obstructive pyelonephritis
• N11.8 Other chronic tubulo-interstitial nephritis
• N11.9 Chronic tubulo-interstitial nephritis, unspecified (this code)