2026 ICD-10-CM Diagnosis Code N11Chronic tubulo-interstitial nephritis
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
Code Classification
Specific Coding for Chronic tubulo-interstitial nephritisOverview
Non-specific codes like N11 require more characters. Use one of these billable codes instead:
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Includes
- chronic infectious interstitial nephritis
- chronic pyelitis
- chronic pyelonephritis
Use Additional Code
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.
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.
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Code HistoryHistory
Questions About N11Overview
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.
