ICD-10-CM · Digestive system
ICD-10-CM · Digestive systemK21.01: Gastro-esophageal reflux disease with esophagitis, with bleeding
K21.01 is the ICD-10-CM code for Gastro-esophageal reflux disease with esophagitis, with bleeding. Billable on U.S. claims with supporting documentation. Chapter: Digestive system. Category: K21.
About this code
Gastro-esophageal reflux disease with esophagitis, with bleeding.
K21.01 is an ICD-10-CM diagnosis code for gastro-esophageal reflux disease with esophagitis, with bleeding. It sits in the 11. Digestive system chapter of the U.S. clinical modification, under category K21.
This code is billable on U.S. healthcare claims when supported by appropriate clinical documentation. The patient chart must establish the diagnosis, capture any clinical detail encoded in the code (severity, laterality, encounter type, complications where applicable), and demonstrate medical necessity for the billed services.
Payer-specific coverage rules vary. Always cross-check against the current Local Coverage Determinations (LCDs) and National Coverage Determinations (NCDs) for the payer adjudicating the claim, plus any specialty-specific CMS Medicare Administrative Contractor guidance.
Billing context
What practitioners watch for on K21.01.
Chapter-level billing guidance for digestive system codes. Code-specific notes ship as the dataset matures.
Documentation
Document anatomic site, acute vs chronic, hemorrhage status, and any associated GERD or other conditions. For colonoscopy, document screening vs diagnostic clearly because they have different coverage and frequency rules.
Common denial categories
- CO-16: Information missing or incorrect on the claim or in supporting documentation. Add documentation specificity that supports the coded detail; resubmit with corrected information.
- CO-50: Service not deemed medically necessary by the payer. Confirm the diagnosis-procedure relationship matches LCD/NCD coverage, attach clinical justification, appeal with documentation.
- CO-11: Diagnosis is inconsistent with the procedure performed. Verify the diagnosis-to-procedure pairing per payer policy; correct the linked diagnosis pointer or the procedure code.
Coverage signal
Coverage rules vary by payer and by plan. Cross-check against the current Local Coverage Determination (LCD) and National Coverage Determination (NCD) for the adjudicating payer. Medonix runs this check automatically during pre-submission scrubbing.
Common specialties
Gastroenterology · Family Medicine · Internal Medicine
Companion CPT codes
Procedures commonly billed alongside K21.01 based on Medonix client production data and CMS coding guidance.
- 45378Diagnostic colonoscopy
- G0121Screening colonoscopy, average risk
- 43239Upper GI endoscopy with biopsy
- 99214Office visit, established, moderate complexity
CPT is a registered trademark of the American Medical Association. Codes shown for educational reference only.
Related codes
Other codes in category K21.
Sources
Where this entry comes from.
- NLM Clinical Tables Search Service: the official U.S. National Library of Medicine API for ICD-10-CM lookup.
- CDC National Center for Health Statistics: annual ICD-10-CM Tabular List release with effective date October 1.
- CMS Medicare Coverage Database: Local Coverage Determinations and National Coverage Determinations for payer-specific rules.
Frequently asked
About ICD-10 code K21.01.
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