ICD-10 K21.9
Billable / SpecificGastro-esophageal reflux disease without esophagitis
About ICD-10-CM K21.9
ICD-10-CM code K21.9 represents Gastro-esophageal reflux disease without esophagitis. This is a billable/specific code in the Digestive System chapter (block K21). The 2026 edition of ICD-10-CM K21.9 became effective on October 1, 2025.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under K21.9. Per CMS ICD-10-CM Tabular 2026.
- Esophageal reflux NOS
Medicare LCD Coverage for K21.9
Local Coverage Determinations (LCDs) from CMS MACs that list K21.9 as a covered diagnosis.
Showing top 10 of 346 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing K21.9.
4 Aetna
5 Medicare
CPT Codes Commonly Billed with K21.9
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 91035 Esophageal pH monitoring — GERD evaluation, heartburn, retrosternal chest pain, dysphagia, asthma with suspected GERD, chronic cough, Barrett Gastroenterology
- 43284 CMS LCD: Billing and Coding: Lower Esophageal Magnetic Sphincter Augmentation CMS LCD
- 43285 CMS LCD: Billing and Coding: Lower Esophageal Magnetic Sphincter Augmentation CMS LCD
- 43257 CMS LCD: Billing and Coding: Stretta Procedure CMS LCD
- 43999 CMS LCD: Billing and Coding: Select Minimally Invasive GERD Procedures CMS LCD
- 49999 CMS LCD: Billing and Coding: Select Minimally Invasive GERD Procedures CMS LCD
Convert K21.9 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 |
|---|---|---|
| K21.9 | 53081 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To K21.9
Other codes in section K20-K31 (Diseases of esophagus, stomach and duodenum).
ICD-10 K21.9, Billing FAQ
Is ICD-10 code K21.9 billable? +
Yes, K21.9 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 K21.9? +
ICD-10 K21.9 includes: Esophageal reflux NOS.
What CPT codes are commonly billed with K21.9? +
Procedures frequently paired with K21.9 include: 91035, 43284, 43285, 43257, 43999.
What ICD-9 codes does K21.9 map to? +
Per CMS GEMs, K21.9 maps to ICD-9 codes: 53081. 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 July 16, 2026.
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