2027 ICD-10-CM Diagnosis Code N11Chronic tubulo-interstitial nephritis

ICD-10-CM Codes›N00–N99›N10-N16›N11

ICD-10-CM N11
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

N11 is a non-billable ICD-10-CM category code for chronic tubulo-interstitial nephritis, so it cannot be submitted on claims. Use a more specific code from this category instead, such as N11.0, N11.1, N11.8, and N11.9.

Code Identity

ICD-10-CM Code
N11
Billable Status
No — Non-Billable Category
Code Describes
Chronic tubulo-interstitial nephritis
Short Description
Chronic tubulo-interstitial nephritis
Same as the full description in the CMS dataset.
Chapter
N10-N16
Renal tubulo-interstitial diseases

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN10-N16Renal tubulo-interstitial diseases
CategoryN11Chronic tubulo-interstitial nephritis
This CodeN11Chronic tubulo-interstitial nephritis

Specific Coding for Chronic tubulo-interstitial nephritisOverview

Non-specific codes like N11 require more characters. Use one of these billable codes instead:

  • Use N11.0 for Nonobstructive reflux-associated chronic pyelonephritis

  • Use N11.1 for Chronic obstructive pyelonephritis

  • Use N11.8 for Other chronic tubulo-interstitial nephritis

  • Use N11.9 for Chronic tubulo-interstitial nephritis, unspecified

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to N11: its own notes plus those printed at block N10-N16 and Chapter 14. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

On N11 itself
  • chronic infectious interstitial nephritis
  • chronic pyelitis
  • chronic pyelonephritis
From Block N10-N16 Renal tubulo-interstitial diseases applies to 35 codes
  • pyelonephritis

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Block N10-N16 Renal tubulo-interstitial diseases applies to 35 codes
  • pyeloureteritis cystica (N28.85)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 14 (N00-N99) Diseases of the genitourinary system applies to 838 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

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

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name N11, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming N11: they are not reported together with it, unless the two conditions are unrelated.

  • N03 Chronic nephritic syndrome
    chronic tubulo-interstitial nephritis (N11.-)

Patient EducationClinical

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.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About N11Overview

What is the ICD-10 code for chronic tubulo-interstitial nephritis?

N11 is the ICD-10-CM category for chronic tubulo-interstitial nephritis, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is N11 (Chronic tubulo-interstitial nephritis) a billable code?

No. This is a category header that groups the codes for chronic tubulo-interstitial nephritis, and headers cannot be submitted on claims. Claims for chronic tubulo-interstitial nephritis need a more specific code from this category, such as N11.0, N11.1, and N11.8.

Can N11 be reported with N28.85?

Not as a rule. The Excludes1 note at block N10-N16, which applies to N11, lists "pyeloureteritis cystica (N28.85)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

Does N11 need an additional code?

When the condition applies, yes. The Use Additional Code note reads: code (B95-B97), to identify infectious agent.. The additional code is reported after N11.