
Navigating the Seasonal Flu Vaccine Requirement
Understanding the Flu Vaccine Requirement for Form I-693
Its purpose is to establish that you are not inadmissible to the United States on public health grounds, as outlined in the Immigration and Nationality Act (INA). A key part of this medical exam is ensuring you have received all required vaccinations.
The Special Rule for the Seasonal Flu Vaccine
The list of required immunizations is determined by the U.S. Centers for Disease Control and Prevention (CDC). While most required vaccines, such as those for measles, mumps, and rubella (MMR), are mandatory year-round, the seasonal influenza (flu) vaccine is a special case.
The CDC has advised USCIS that the flu vaccine’s availability is seasonal.
For immigration purposes, the CDC defines the annual flu season as running from October 1 to March 31.
How This Affects Your Application (As of September 2025)
Understanding this rule is crucial for timing your medical exam. With the 2025-2026 flu season beginning next week, here is how the requirement applies:
The only exception is if the vaccine is medically inappropriate for you, which the Civil Surgeon must document.
The Civil Surgeon will note on your Form I-693 that the vaccine is “Not in season” or “Not available.”
