ICD-10-CM 2027
ICD-10 code for urinary stone
From the official ICD-10-CM alphabetic index entry “Stone (s) › urinary (duct) (impacted) (passage)”. Page updated September 29, 2026.
About coding urinary stone
The ICD-10-CM code for urinary stone is N20.9 (Urinary calculus, unspecified). The official index lists 3 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on N20.9.
Within N20, choose N20.9 (Urinary calculus, unspecified) only when documentation doesn't support a more specific option: calculus of kidney (N20.0), calculus of ureter (N20.1) and calculus of kidney with calculus of ureter (N20.2).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 693 (Urinary Stones with MCC, relative weight 1.3168) and DRG 694 (Urinary Stones without MCC, relative weight 0.7815), in MDC 11 (Diseases and Disorders of the Kidney and Urinary Tract), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific urinary stone codes (official index)
Common questions about urinary stone ICD-10 codes
What is the ICD-10 code for urinary stone?
- N20.9 — Urinary calculus, unspecified. More specific codes apply when the documentation supports them: N21.0, N21.9, N21.8.
What is the ICD-10 code for bladder urinary stone?
- N21.0 — Calculus in bladder.
What is the ICD-10 code for lower tract urinary stone?
- N21.9 — Calculus of lower urinary tract, unspecified.
Is N20.9 billable?
- Yes. N20.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can N20.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict N20.9 as a principal diagnosis.
Is N20.9 a CC or MCC?
- No. N20.9 is neither a CC nor an MCC under MS-DRG v44.0.