ICD-10-CM Tabular Index · Chapter 11 · FY 2026 K20–K31
Diseases of esophagus, stomach and duodenum (K20-K31) ICD-10-CM
The K20–K31 section covers diseases of esophagus, stomach and duodenum with 135 ICD-10-CM diagnosis codes, of which 105 are billable in fiscal year 2026. The section is organized into the 11 code ranges listed below.
✓ Built from the official CMS FY 2026 datasetEffective Oct 1, 2025 – Sep 30, 2026
11
Code Ranges
135
Diagnosis Codes
105
Billable Codes
K20–K31
Code Range
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
The info icon previews the code ranges inside each row and its instructional notations from the official Tabular List.
About the K20–K31 Code Range
ICD-10 codes K20-K31 cover diseases affecting the esophagus, stomach, and duodenum, including inflammation, ulcers, reflux conditions, and other unique digestive tract disorders.
This range includes codes for esophagitis such as eosinophilic esophagitis (K20.0), gastro-esophageal reflux disease (GERD) with or without esophagitis (K21), and complications like Barrett's esophagus (K22.7). It also addresses esophageal conditions like achalasia (K22.0), ulcers, obstructions, and perforations. The stomach and duodenum diseases covered include acute and chronic ulcers with hemorrhage or perforation (K25-K28), gastritis and duodenitis (K29), functional dyspepsia (K30), and various structural or motility disorders such as gastroparesis (K31.84) and pyloric stenosis (K31.1). These codes assist in accurately coding common and complex gastrointestinal diagnoses including synonyms like “acid reflux,” “gastric ulcer with hemorrhage,” and “eosinophilic duodenitis,” helping clinicians and coders pinpoint specific digestive tract disorders.
Questions About This Page
How many codes are in the K20-K31 range?
The K20-K31 range contains 135 ICD-10-CM diagnosis codes in FY 2026. 105 of them are billable, and the rest are category headers that organize the section.
What conditions does K20-K31 cover?
The range covers diseases of esophagus, stomach and duodenum. The code ranges listed above break it into groups of related conditions, and each one links to its own page with the full code list.
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.
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.
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
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.
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
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.
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
erosion (acute) of stomach
pylorus ulcer (peptic)
stomach ulcer (peptic)
Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.
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.
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
erosion (acute) of duodenum
duodenum ulcer (peptic)
postpyloric ulcer (peptic)
Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.
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.
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
gastroduodenal ulcer NOS
peptic ulcer NOS
Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.
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.
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
anastomotic ulcer (peptic) or erosion
gastrocolic ulcer (peptic) or erosion
gastrointestinal ulcer (peptic) or erosion
gastrojejunal ulcer (peptic) or erosion
jejunal ulcer (peptic) or erosion
marginal ulcer (peptic) or erosion
stomal ulcer (peptic) or erosion
Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.
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.
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.
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Indigestion
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.
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
functional disorders of stomach
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
