K31 vs K59

K31 (Other diseases of stomach and duodenum) compared with K59 (Other functional intestinal disorders), from the official CMS tabular data. Both may be reported when both conditions are documented (Excludes2).

Can these codes be reported together?

Yes, when both are documented. K59 carries an Excludes2 note covering K31: “functional disorders of stomach (K31.-)”

Excludes2 marks distinct conditions — both may be reported when both are documented.

Side by side

	K31Other diseases of stomach and duodenum	K59Other functional intestinal disorders
Billing status	Non-billable header Report instead: K31.0, K31.1, K31.2, K31.3, K31.4	Non-billable header Report instead: K59.00, K59.01, K59.02, K59.03, K59.04
Classification	K00-K95 — Diseases of the Digestive System (K00-K95)	K00-K95 — Diseases of the Digestive System (K00-K95)
Definition	Other diseases of stomach and duodenum is a non-billable ICD-10-CM category code (K31).	Other functional intestinal disorders is a non-billable ICD-10-CM category code (K59).
Includes	functional disorders of stomach	—

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Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources