ICD-10-CM > K00-K95 > K20-K31 > K21 > K21.0 K21.0 Gastro-esophageal reflux disease with esophagitis Non-Billable/Non-Specific Codes K21.00Gastro-esophageal reflux disease with esophagitis, without bleedingK21.01Gastro-esophageal reflux disease with esophagitis, with bleeding