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ICD-10-CM tabular list

K20-K31Diseases of esophagus, stomach and duodenum

ICD-10-CM codes K20-K31 cover diseases of esophagus, stomach and duodenum, within diseases of the digestive system. The block holds 135 codes across 11 categories, of which 105 are billable and 30 are header codes that cannot be submitted on a claim.

Excludes2 — not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

  • hiatus hernia (K44.-)

Risk adjustment in K20-K31

0 codes in this block map to a CMS-HCC, which means the diagnosis carries a risk-adjustment payment when it is documented and coded. Under-coding here is money left on the table; over-coding here is what audits are for.

  • HCC 78 Intestinal Obstruction/Perforation

What else to watch in K20-K31

  • 102 codes are named in Medicare coverage policies. An LCD or NCD lists them as supporting medical necessity, or explicitly as not supporting it. Which applies depends on the MAC for your state.

Categories in K20-K31

ICD-10-CMFY2026-Apr· effective April 1, 2026