Gastro-esophageal reflux disease (K21) ICD-10-CM
The K21 code range covers gastro-esophageal reflux disease with 5 ICD-10-CM diagnosis codes. 3 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
- newborn esophageal reflux P78.83
Codes in the K21 Range 5 codes · 3 billable
- K21 Gastro-esophageal reflux diseaseNon-billable
- K21.0 Gastro-esophageal reflux disease with esophagitisNon-billable
- K21.00 Gastro-esophageal reflux disease with esophagitis, without bleeding
- K21.01 Gastro-esophageal reflux disease with esophagitis, with bleeding
- K21.9 Gastro-esophageal reflux disease without esophagitis
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the K21 range.
Duodenogastric Reflux
Retrograde flow of duodenal contents (BILE ACIDS; PANCREATIC JUICE) into the STOMACH.
Laryngopharyngeal Reflux
Back flow of gastric contents to the LARYNGOPHARYNX where it comes in contact with tissues of the upper aerodigestive tract. Laryngopharyngeal reflux is an extraesophageal manifestation of GASTROESOPHAGEAL REFLUX.
About the K21 Code Range
ICD-10 codes K21 to K21.9 classify different forms of gastro-esophageal reflux disease (GERD), including cases with or without esophagitis and bleeding. These codes precisely identify the severity and complications of acid reflux affecting the esophagus.
The ICD-10 code for gastro-esophageal reflux disease (K21) covers the general condition of acid reflux. Subcategories like K21.0 specify GERD with esophagitis, and further detail is provided by K21.00 for cases without bleeding, which includes synonymous terms such as "alkaline reflux disease," "esophagogastric ulcer," and "gastroesophagitis." When bleeding occurs due to erosive reflux, K21.01 is used, capturing conditions like esophageal hemorrhage and bleeding. The code K21.9 represents GERD without esophagitis and encompasses various related terms such as "acid reflux," "laryngopharyngeal reflux," and "non-erosive gastro-esophageal reflux disease." These ICD-10 codes help healthcare professionals document the nature and complications of GERD accurately for diagnosis, treatment, and reporting purposes.
Questions About This Page
How many billable codes are in the K21 range?
Of the 5 codes in this range, 3 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the K21 range classify?
The range classifies gastro-esophageal reflux disease. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
