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K52.21 vs T78.110S

K52.21 (Food protein-induced enterocolitis syndrome) compared with T78.110S (Other adverse food reactions due to milk and dairy products with tolerance to baked milk, sequela), from the official CMS tabular data.

Summary

These codes can be reported together when both conditions are documented, because T78.110S lists K52.21 under Excludes2, which marks them as distinct conditions.

Official rule
What is different?

The conditions named and chapter.K52.21 is “Food protein-induced enterocolitis syndrome”; T78.110S is “Other adverse food reactions due to milk and dairy products with tolerance to baked milk, sequela”. K52.21 sits in K00-K95 — Diseases of the Digestive System (K00-K95); T78.110S in S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88).

Registry fact

Can these codes be reported together?

Yes, when both are documented.T78.110S lists K52.21 under Excludes2: “food protein-induced enterocolitis syndrome (K52.21)”. Excludes2 marks distinct conditions that may both be reported when both are documented.

Official ruleGuide: Excludes1 vs Excludes2

Is there an Excludes1 relationship?

None.Neither entry carries an Excludes1 note that names the other code. K52.21 carries 2 Excludes1 notes and T78.110S carries 4 Excludes1 notes covering other codes; the side-by-side table quotes them.

Official rule

Is there an Excludes2 relationship?

Yes.T78.110S’s tabular entry: “food protein-induced enterocolitis syndrome (K52.21)”. The note covers K52.21.

Official ruleGuide: Excludes1 vs Excludes2

Is one more specific?

Not comparable.The codes sit in different categories; specificity is only comparable within one category.

Is one a parent or header code?

No.Both are billable codes, and neither contains the other.

Registry fact

Are there sequencing instructions?

None.Neither entry carries a Code First or Use Additional Code note that names the other.

Official rule

Are there other coding relationships?

None found.No laterality, encounter-phase, Table of Neoplasms, Table of Drugs and Chemicals, or history-versus-active-disease relationship links these codes.

MedCoder-derived

Official rule: a tabular instructional note or a section of the ICD-10-CM Official Guidelines, quoted as published. Registry fact: the codes’ own published attributes (titles, billable status, position in the hierarchy, code set). MedCoder-derived: a reading MedCoder computes from those facts; it is not itself a rule. How to read the labels

Can these codes be reported together?

Informational

Excludes2 relationship

T78.110S
Other adverse food reactions due to milk and dairy products with tolerance to baked milk, sequela
↔
K52.21
Food protein-induced enterocolitis syndrome

What we found

Yes, when both are documented.T78.110S carries an Excludes2 note covering K52.21: “food protein-induced enterocolitis syndrome (K52.21)”

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

What to review

Report both only when the documentation supports both conditions; otherwise report the one documented.

Guide: Excludes1 vs Excludes2Check these on a claim

Why it matters

An Excludes2 note means the excluded condition is not part of the code above it, but a patient can have both. Report both when both are documented.

Source / rule

CMS ICD-10-CM tabular instructional notes

Official guidance behind these answers

  • Section I.A.12.b — Excludes2 · applies to: Excludes2

    A type 2 Excludes note represents “Not included here.” An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

    ICD-10-CM Official Guidelines FY2026

Quoted from the ICD-10-CM Official Guidelines for Coding and Reporting in effect for the release shown. The tabular notes above are the code-level instruction; these sections are the convention that says how such a note is applied. Source document (CMS PDF) · Release and checksum

Side by side

K52.21Food protein-induced enterocolitis syndromeT78.110SOther adverse food reactions due to milk and dairy products with tolerance to baked milk, sequela
Billing statusBillableBillable
ClassificationK00-K95 — Diseases of the Digestive System (K00-K95)S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)
DefinitionFood protein-induced enterocolitis syndrome is a billable ICD-10-CM diagnosis code (K52.21).Other adverse food reactions due to milk and dairy products with tolerance to baked milk, sequela is a billable ICD-10-CM diagnosis code (T78.110S).
7th character—The appropriate 7th character is to be added to each code from category T78
Includes
noninfective inflammatory bowel disease
FPIES
—
Excludes1
irritable bowel syndrome (K58.-)
megacolon (K59.3-)
Other adverse food reaction due to milk and dairy products with reactivity to baked milk (T78.111)
anaphylactic reaction or shock due to adverse food reaction (T78.0-)
anaphylactic reaction due to food (T78.0-)
bacterial food borne intoxications (A05.-)
Excludes2
allergic eosinophilic colitis (K52.82)
allergic eosinophilic esophagitis (K20.0)
allergic eosinophilic gastritis (K52.81)
allergic eosinophilic gastroenteritis (K52.81)
allergic and dietetic gastroenteritis and colitis (K52.29)
allergic rhinitis due to food (J30.5)
dermatitis due to food in contact with skin (L23.6, L24.6, L25.4)
dermatitis due to ingested food (L27.2)
food protein-induced enterocolitis syndrome (K52.21)
food protein-induced enteropathy (K52.22)
complications of surgical and medical care NEC (T80-T88)
Use additional code
code for hypovolemic shock, if present (R57.1)
code to identify type of food allergy (Z91.01-, Z91.02-)
code to identify the type of reaction, if applicable
Code also—
, if applicable, place of occurrence, such as:
highway rest stop (Y92.523)
school (private) (public) (state) as the place of occurrence of the external cause (Y92.21-)
service areas as the place of occurrence of the external cause (Y92.52-)
single-family non-institutional (private) house as the place of occurrence of the external cause (Y92.01-)
transport vehicle as the place of occurrence of the external cause (Y92.81-)

Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on.

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Derived from the official CMS ICD-10-CM tabular data (FY2027). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources