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Compare/A09 vs K52.9

A09 vs K52.9

A09 (Infectious gastroenteritis and colitis, unspecified) compared with K52.9 (Noninfective gastroenteritis and colitis, unspecified), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.

Can these codes be reported together?

No — do not report together. A09 carries an Excludes1 note covering K52.9: “colitis NOS (K52.9)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

No — do not report together. A09 carries an Excludes1 note covering K52.9: “enteritis NOS (K52.9)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

No — do not report together. A09 carries an Excludes1 note covering K52.9: “gastroenteritis NOS (K52.9)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

No — do not report together. A09 carries an Excludes1 note covering K52.9: “noninfective gastroenteritis and colitis, unspecified (K52.9)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

No — do not report together. K52.9 carries an Excludes1 note covering A09: “infectious gastroenteritis and colitis NOS (A09)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Side by side

A09Infectious gastroenteritis and colitis, unspecifiedK52.9Noninfective gastroenteritis and colitis, unspecified
Billing statusBillableBillable
ClassificationA00-B99 — Certain Infectious and Parasitic Diseases (A00-B99)K00-K95 — Diseases of the Digestive System (K00-K95)
DefinitionInfectious gastroenteritis and colitis, unspecified is a billable ICD-10-CM diagnosis code (A09).Noninfective gastroenteritis and colitis, unspecified is a billable ICD-10-CM diagnosis code (K52.9).
Includes
Infectious colitis NOS
Infectious enteritis NOS
Infectious gastroenteritis NOS
noninfective inflammatory bowel disease
Colitis NOS
Enteritis NOS
Gastroenteritis NOS

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