ICD-10 E20.818
Billable / Specific HCC v28: 23Other specified hypoparathyroidism due to impaired parathyroid hormone secretion
About ICD-10-CM E20.818
ICD-10-CM code E20.818 represents Other specified hypoparathyroidism due to impaired parathyroid hormone secretion. This is a billable/specific code in the Endocrine, Nutritional, and Metabolic chapter (block E20). The 2026 edition of ICD-10-CM E20.818 became effective on October 1, 2025.
Coding Tips for E20.818
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
E20.818 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.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under E20.818. Per CMS ICD-10-CM Tabular 2026.
- Familial isolated hypoparathyroidism
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.
Medicare LCD Coverage for E20.818
Local Coverage Determinations (LCDs) from CMS MACs that list E20.818 as a covered diagnosis.
Showing top 10 of 68 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing E20.818.
1 Cigna
5 Medicare
CPT Codes Commonly Billed with E20.818
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 83970 CMS LCD: Billing and Coding: Parathormone (Parathyroid Hormone) CMS LCD
Codes Adjacent To E20.818
Other codes in section E20-E35 (Disorders of other endocrine glands).
ICD-10 E20.818, Billing FAQ
Is ICD-10 code E20.818 billable? +
Yes, E20.818 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 E20.818? +
ICD-10 E20.818 includes: Familial isolated hypoparathyroidism.
Does E20.818 affect Medicare Advantage HCC risk adjustment? +
Yes. E20.818 maps to CMS-HCC v28 category 23. Capture this diagnosis annually for accurate Medicare Advantage risk score.
What CPT codes are commonly billed with E20.818? +
Procedures frequently paired with E20.818 include: 83970.
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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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