2026 ICD-10-CM Diagnosis Code T78.079SAnaphylactic reaction due to milk and dairy products, unspecified, sequela
T78.079S is a billable ICD-10-CM diagnosis code for anaphylactic reaction due to milk and dairy products, unspecified, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 922 through 923. The code is exempt from POA reporting. Coders also document this condition as Cow's milk protein-induced anaphylaxis.
Code Identity
Code Classification
Present on Admission (POA)Billing
T78.079S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Cow's milk protein-induced anaphylaxis
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Adverse effects, not elsewhere classified (T78). Use the following options for the applicable episode of care:
- A - initial encounter
- D - subsequent encounter
- S - sequela
Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.
Code History & ChangesHistory
New Code T78.079S was added to the ICD-10-CM code set for FY 2026, effective October 1, 2025.
Replacement T78.079S replaces the following previously assigned code(s):
- T78.07XS - Anaphyl reaction due to milk and dairy products, sequela
Questions About T78.079SOverview
Is T78.079S a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report anaphylactic reaction due to milk and dairy products, unspecified, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T78.079S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the anaphylactic reaction due to milk and dairy products, unspecified itself has resolved, not the original event.
What MS-DRG does T78.079S group to?
When anaphylactic reaction due to milk and dairy products, unspecified, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.
Is T78.079S exempt from POA reporting?
Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for anaphylactic reaction due to milk and dairy products, unspecified, sequela on inpatient claims.
