ICD-10 N25.81
Billable / Specific HCC v28: 23 CCSecondary hyperparathyroidism of renal origin
About ICD-10-CM N25.81
ICD-10-CM code N25.81 represents Secondary hyperparathyroidism of renal origin. This is a billable/specific code in the Genitourinary System chapter (block N25). The 2026 edition of ICD-10-CM N25.81 became effective on October 1, 2025.
Coding Tips for N25.81
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
N25.81 is a CMS-HCC v28 risk-adjustment code (category 23). To count for the patient Risk Adjustment Factor (RAF), document the diagnosis with MEAT language each calendar year: Monitored, Evaluated, Assessed, Treated. A diagnosis on the problem list alone does not satisfy CMS RADV audit standards. Include the diagnosis in the assessment with current status and current treatment plan.
N25.81 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.
Type 1 Excludes
Pure excludes, these codes can never be coded together with N25.81. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- secondary hyperparathyroidism, non-renal (E21.1)
Type 2 Excludes
Not included here, the excluded code is not part of N25.81, but a patient may have both conditions at the same time. Both codes may be coded together when applicable.
- metabolic disorders classifiable to E70-E88
Medicare Advantage HCC Impact
Capture this diagnosis annually for accurate risk adjustment. Missed HCC captures are the #1 revenue leak in Medicare Advantage risk programs.
Inpatient DRG Impact, CC
codes Secondary hyperparathyroidism of renal origin. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for N25.81
Local Coverage Determinations (LCDs) from CMS MACs that list N25.81 as a covered diagnosis.
Showing top 10 of 30 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing N25.81.
1 Aetna
1 Cigna
5 Medicare
CPT Codes Commonly Billed with N25.81
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 90999 CMS LCD: Billing and Coding: Frequency of Hemodialysis CMS LCD
Convert N25.81 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 |
|---|---|---|
| N25.81 | 58881 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To N25.81
Other codes in section N25-N29 (Other disorders of kidney and ureter).
ICD-10 N25.81, Billing FAQ
Is ICD-10 code N25.81 billable? +
Yes, N25.81 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 N25.81? +
Type 1 Excludes (never code together with N25.81): secondary hyperparathyroidism, non-renal (E21.1)
What codes are Type 2 Excludes for N25.81? +
Type 2 Excludes (may be coded together when both conditions exist): metabolic disorders classifiable to E70-E88
Does N25.81 affect Medicare Advantage HCC risk adjustment? +
Yes. N25.81 maps to CMS-HCC v28 category 23. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Is N25.81 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 N25.81? +
Procedures frequently paired with N25.81 include: 90999.
What ICD-9 codes does N25.81 map to? +
Per CMS GEMs, N25.81 maps to ICD-9 codes: 58881. 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 May 31, 2026.
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