In simple words: This code tracks severe allergic reactions to the DTP vaccine in children 13 and younger.

This code is used for performance measurement and tracks instances where a patient experienced anaphylaxis (a severe, potentially life-threatening allergic reaction) due to the tetanus, diphtheria, or pertussis vaccine at any time on or before their 13th birthday.

Example 1: A 12-year-old child receives a DTaP vaccination and develops hives, difficulty breathing, and swelling of the face shortly after. This reaction is documented as anaphylaxis, and M1161 is reported., A 5-year-old child experiences anaphylaxis after their first DTaP dose. Subsequent doses are not administered, and the event is coded with M1161., A review of patient records identifies a 10-year-old who had an undocumented allergic reaction to DTaP at age 7. While retrospectively coding the encounter, the provider codes M1161 if there is supporting documentation from the visit.

Documentation of the anaphylactic reaction, including symptoms, onset time relative to vaccination, and treatment provided. Patient's age at the time of the reaction, confirming it occurred on or before their 13th birthday. Confirmation that the reaction was specifically due to the tetanus, diphtheria, or pertussis vaccine, and not another component or co-administered vaccine.

** This is a performance measurement code used to track adverse reactions to vaccines. It is not used for billing or reimbursement purposes. Always consult the latest coding guidelines and program-specific instructions for accurate reporting.