N21 – Calculus of lower urinary tract
ICD-10-CM 2027 diagnosis code · Urolithiasis
ICD-10-CM code
N21
- Code
N21(claims format:N21)- Description
- Calculus of lower urinary tract
- Billable
- No – use a more specific code below
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 14. Diseases of the genitourinary system (N00-N99)
- Block
- N20-N23 Urolithiasis
Billable codes under N21
N21 is a header code and cannot be used on claims. Choose the most specific code:
Notes for N21
Includes:
- calculus of lower urinary tract with cystitis and urethritis
Frequently asked questions
What is ICD-10 code N21?
N21 is the ICD-10-CM code for calculus of lower urinary tract, in the block N20-N23 (Urolithiasis).
Is N21 a billable code?
No. N21 is a header code with more specific child codes; report one of the billable codes listed above.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.