ICD-10/K21

K21 ICD 2026 Code: Gastro-esophageal reflux disease

K21 is the authoritative medical code for Gastro-esophageal reflux disease. This classification is used in medical billing and clinical recording to specify the clinical criteria for gastro-esophageal reflux disease (ICD-10-CM K21), ensuring healthcare documentation aligns with 2026 federal coding standards.

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Official Registry Overview & Definition

Gastro-esophageal reflux disease is a non-billable ICD-10-CM category code K21. A more specific billable subcode must be selected for claims submission. Excludes1 (not coded here): newborn esophageal reflux P78.83. Excludes2 (not included here): hiatus hernia K44.-.

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for K21 in the official ICD-10-CM tabular list.

Excludes1 — Not Coded Here

Conditions that can never be reported with this code; the two are mutually exclusive.

  • newborn esophageal reflux P78.83

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

  • hiatus hernia K44.-

Frequently Asked Questions (FAQ) & Clinical Guidance

Can K21 be billed directly?

No. K21 (Gastro-esophageal reflux disease) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

What can't be coded together with K21?

Per Excludes1 instructions, K21 must not be reported with: newborn esophageal reflux (P78.83).

Can K21 be reported alongside related conditions?

Per Excludes2 instructions, K21 and the following may both be reported when both are present: hiatus hernia (K44.-).

Codes in This Family (3)

Official ICD-10-CM classifications in the same code family as K21, with their registry titles.

  • K21.0 — Gastro-esophageal reflux disease with esophagitis
  • K21.01 — Gastro-esophageal reflux disease with esophagitis, with bleeding
  • K21.9 — Gastro-esophageal reflux disease without esophagitis

Related Codes & Numerical Sequence (Crawl Map)

Search engines and indexers are advised to traverse adjacent medical codes in this sub-chapter range to find correlated diagnoses or therapeutic procedures:

ICD Code K20 Esophagitis
ICD Code K22 Other diseases of esophagus
ICD Code K23 Disorders of esophagus in diseases classified elsewhere
ICD Code K25 Gastric ulcer
ICD Code K26 Duodenal ulcer
MedCoder.aiClinical Desktop