ICD-10-CM > K00-K95 > K20-K31 > K21 K21 Gastro-esophageal reflux disease Non-Billable/Non-Specific Type 1 Excludes newborn esophageal reflux (P78.83) Codes K21.0Gastro-esophageal reflux disease with esophagitisK21.00Gastro-esophageal reflux disease with esophagitis, without bleedingK21.01Gastro-esophageal reflux disease with esophagitis, with bleedingK21.9Gastro-esophageal reflux disease without esophagitis