ICD-10 N21.9
Billable / SpecificCalculus of lower urinary tract, unspecified
About ICD-10-CM N21.9
ICD-10-CM code N21.9 represents Calculus of lower urinary tract, unspecified. This is a billable/specific code in the Genitourinary System chapter (block N21). The 2026 edition of ICD-10-CM N21.9 became effective on October 1, 2025.
Type 1 Excludes
Pure excludes, these codes can never be coded together with N21.9. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- calculus of urinary tract NOS (N20.9)
Medicare LCD Coverage for N21.9
Local Coverage Determinations (LCDs) from CMS MACs that list N21.9 as a covered diagnosis.
This doesn't mean the code isn't covered, it means no MAC has issued a Local Coverage Determination naming this specific code. Coverage may still apply under National Coverage Determinations or general medical-necessity rules.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing N21.9.
1 Cigna
CPT Codes Commonly Billed with N21.9
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Convert N21.9 to ICD-9-CM
Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.
| ICD-10 | ICD-9 | Mapping Flags |
|---|---|---|
| N21.9 | 5949 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To N21.9
Other codes in section N20-N23 (Urolithiasis).
ICD-10 N21.9, Billing FAQ
Is ICD-10 code N21.9 billable? +
Yes, N21.9 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What codes are Type 1 Excludes for N21.9? +
Type 1 Excludes (never code together with N21.9): calculus of urinary tract NOS (N20.9)
What ICD-9 codes does N21.9 map to? +
Per CMS GEMs, N21.9 maps to ICD-9 codes: 5949. Useful for legacy data review and historical claim analysis.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on June 1, 2026.
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