ICD-10 N20.1
Billable / Specific CCCalculus of ureter
About ICD-10-CM N20.1
ICD-10-CM code N20.1 represents Calculus of ureter. This is a billable/specific code in the Genitourinary System chapter (block N20). The 2026 edition of ICD-10-CM N20.1 became effective on October 1, 2025.
Coding Tips for N20.1
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
N20.1 is designated CC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-CC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag CC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under N20.1. Per CMS ICD-10-CM Tabular 2026.
- Calculus of the ureteropelvic junction
- Ureteric stone
Inpatient DRG Impact, CC
codes Calculus of ureter. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for N20.1
Local Coverage Determinations (LCDs) from CMS MACs that list N20.1 as a covered diagnosis.
Showing top 10 of 19 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing N20.1.
5 Medicare
CPT Codes Commonly Billed with N20.1
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 50590 Lithotripsy — kidney stone, ureter stone, kidney/ureter stone, obstructive uropathy, abdominal pain, abnormal urine Urology
Convert N20.1 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 |
|---|---|---|
| N20.1 | 5921 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To N20.1
Other codes in section N20-N23 (Urolithiasis).
ICD-10 N20.1, Billing FAQ
Is ICD-10 code N20.1 billable? +
Yes, N20.1 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What other names or terms map to N20.1? +
ICD-10 N20.1 includes: Calculus of the ureteropelvic junction; Ureteric stone.
Is N20.1 a CC or MCC for inpatient DRG? +
Yes, this code is designated as CC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
What CPT codes are commonly billed with N20.1? +
Procedures frequently paired with N20.1 include: 50590.
What ICD-9 codes does N20.1 map to? +
Per CMS GEMs, N20.1 maps to ICD-9 codes: 5921. 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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