ICD-10 K21
Non-Billable HeaderGastro-esophageal reflux disease
About ICD-10-CM K21
ICD-10-CM code K21 represents Gastro-esophageal reflux disease. This is a non-billable header code in the Digestive System chapter (block K21). The 2026 edition of ICD-10-CM K21 became effective on October 1, 2025. Non-billable codes cannot be used as a primary or secondary diagnosis on a claim, use a more specific child code instead.
Type 1 Excludes
Pure excludes, these codes can never be coded together with K21. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- newborn esophageal reflux (P78.83)
Medicare LCD Coverage for K21
Local Coverage Determinations (LCDs) from CMS MACs that list K21 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 K21.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but K21 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with K21
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.
Codes Adjacent To K21
Other codes in section K20-K31 (Diseases of esophagus, stomach and duodenum).
ICD-10 K21, Billing FAQ
Is ICD-10 code K21 billable? +
No, K21 is a non-billable header code. Use a more specific child code from block K21 when submitting claims.
What codes are Type 1 Excludes for K21? +
Type 1 Excludes (never code together with K21): newborn esophageal reflux (P78.83)
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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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