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U.S. ICD-10-CM · April 2026

K21 ICD-10-CM Code: Gastro-esophageal reflux disease

A clear reference for the official code description, hierarchy, and related coding information from the April 2026 U.S. release.

Code definition

Official description

K21

Gastro-esophageal reflux disease

ICD-10-CM diagnosis code · United States clinical modification

Classification

Where K21 sits

  1. 1

    Chapter 11

    Diseases of the digestive system (K00-K95)

  2. 2

    Section

    Diseases of esophagus, stomach and duodenum (K20-K31)

  3. 3

    Category K21

    Gastro-esophageal reflux disease

  4. 4

    Code K21

    Gastro-esophageal reflux disease

More specific choices

Codes under K21

K21 is a non-billable category. Choose the child code that best matches the documented diagnosis.

Documentation details

Notes for this code

Inclusion terms

No inclusion terms are listed for K21.

Code first

No “code first” instruction is listed for K21.

Use additional code

No “use additional code” instruction is listed for K21.

Excludes1

Conditions that should not be reported together with this code.

  • newborn esophageal reflux (P78.83)

Excludes2

Conditions not included here that may be reported separately when present.

No Excludes2 note is listed for K21.

Transparency

Source and release

Data release

U.S. ICD-10-CM · April 2026

Effective date

Apr 1, 2026

This reference is generated from Vero’s ICD-10-CM description, hierarchy, and code-note dataset. The visible content and structured data share that source.

Review the CDC/NCHS ICD-10-CM source

Code-specific guidance

Frequently asked questions

What does ICD-10-CM code K21 mean?

K21 is the April 2026 U.S. ICD-10-CM code for “Gastro-esophageal reflux disease.”

Is K21 a billable or specific ICD-10-CM code?

No. K21 has more specific child codes in the April 2026 reference data. Select the code that matches the documentation and confirm the active code set and payer requirements.

Where is K21 located in ICD-10-CM?

K21 is listed in Chapter 11, Diseases of the digestive system (K00-K95), within Diseases of esophagus, stomach and duodenum (K20-K31) (K20–K31), under category K21, Gastro-esophageal reflux disease.

What coding notes are listed for K21?

No inclusion terms are listed for K21 in this reference record. No code-first instruction is listed. Excludes1 notes: newborn esophageal reflux (P78.83). No Excludes2 note is listed.

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