When Should You Get a Flu Shot, and Who Is Eligible for Free Vaccination in 2026?

When Should You Get a Flu Shot, and Who Is Eligible for Free Vaccination in 2026?

As the weather starts to cool, many people wonder when they should get their flu shot.

You may worry that getting vaccinated too early could cause the protection to weaken before winter arrives, or wonder whether it would be okay to get vaccinated a little later.

In particular, during the 2026–2027 season, the age range eligible for government-supported influenza vaccination for children has been expanded.

Until the previous season, free vaccination was available to children from 6 months through 13 years of age. This season, eligibility has been expanded through age 14.

As a result, more children and adolescents, including some born in 2012, can receive the vaccine free of charge.

This article provides an easy-to-understand summary of the best time to get a flu shot, who is eligible for free vaccination in 2026, and the vaccination schedule by age group.

When Is the Best Time to Get a Flu Shot?

Influenza, commonly called the flu, is an acute respiratory infectious disease that can cause a sudden high fever, severe muscle aches, headache, cough, and fatigue, unlike the common cold.

Protection does not develop immediately after vaccination.

It takes about two weeks for the body to produce antibodies that respond to the influenza virus after vaccination.

Therefore, it is best to complete vaccination before flu activity becomes widespread.

Generally, October through November is considered a good time to get a flu shot.

However, the start date for government-funded free vaccination differs depending on the eligible group, so you can get vaccinated when your scheduled period begins.

There is no need to give up on vaccination for the year just because you missed the recommended timing.

Even if flu season is already underway, getting vaccinated later may still be helpful if you have not yet received the vaccine.

Children, pregnant women, older adults, and people with chronic diseases have a relatively higher risk of complications such as pneumonia or worsening of existing conditions after influenza infection. Therefore, it is important for them to check the vaccination schedule.

How Has Free Vaccination Eligibility for Children Expanded in 2026?

The most notable change in the 2026–2027 national influenza vaccination program is the expansion of the eligible age range for children.

Previously, free vaccination was available through age 13, starting at 6 months of age. Beginning this year, children from 6 months through 14 years of age can receive free vaccination.

Specifically, children born between January 1, 2012, and August 31, 2026, are eligible.

They can receive the vaccine free of charge at designated participating medical institutions and public health centers nationwide, regardless of their registered address.

However, vaccine availability and vaccination hours may vary by medical institution, so it is best to check before visiting.

The start date for children's vaccination is divided according to the number of doses required.

Children aged 6 months to under 9 years who are receiving the flu vaccine for the first time or whose previous vaccination history is unknown and who require two doses can be vaccinated starting September 21, 2026.

Children who need two doses begin the program earlier than other groups because a specific interval is usually required between the two doses.

Children who need only one dose each year can receive free vaccination starting September 28, 2026.

Free vaccination for children will continue through April 30, 2027, for all eligible children.

The exact number of doses required may vary depending on previous vaccination records. It is safest to check the immunization record or consult the physician conducting the pre-vaccination assessment.

Can Pregnant Women Receive Free Vaccination Regardless of Gestational Age?

Pregnant women whose pregnancy has been confirmed are also eligible for government-funded free vaccination.

They can be vaccinated at any stage of pregnancy, from early pregnancy through the later stages, regardless of gestational age.

The vaccination period is from September 21, 2026, through April 30, 2027.

When visiting a medical institution, you should bring documentation confirming the pregnancy, such as a maternal health booklet or pregnancy confirmation certificate.

Some people may be concerned about getting a flu shot during pregnancy, but the Korea Disease Control and Prevention Agency recommends influenza vaccination during flu season regardless of gestational age.

If you have concerns about your health condition or previous adverse reactions to vaccines, it is best to inform the medical staff before vaccination.

What Is the Free Vaccination Schedule for Adults Aged 65 and Older?

Adults aged 65 and older can also receive free flu vaccination.

Those eligible during the 2026–2027 season are people born on or before December 31, 1961.

To reduce the number of people arriving for vaccination all at once at the beginning of the program, different start dates have been set for each age group.

People aged 75 and older can receive free vaccination starting October 12, 2026; those aged 70 to 74, starting October 15; and those aged 65 to 69, starting October 19.

The end date is the same for all age groups: April 30, 2027.

Adults aged 65 and older may also be eligible for COVID-19 vaccination during the 2026–2027 season. The influenza and COVID-19 vaccines can be administered on the same day.

If you want to receive both vaccines at the same time, consult the medical staff and have them administered at different injection sites.

Where Can You Get a Free Flu Shot?

Government-funded free vaccination is available at designated participating medical institutions and public health centers nationwide, regardless of your registered address.

However, not every hospital provides free vaccination.

It is best to search for a nearby participating medical institution through the Korea Disease Control and Prevention Agency's Immunization Assistant website before visiting.

The available vaccines and inventory may vary by hospital, so calling ahead to confirm whether vaccination is available can help prevent a wasted trip.

On the day of vaccination, choose a day when you are feeling well. If you have a fever or an acute illness, you should receive a pre-vaccination assessment from the medical staff and then decide whether to get vaccinated.

Considering the time needed for antibodies to develop, it is best to get a flu shot between October and November, before flu activity becomes widespread.

However, because the start date for government-funded free vaccination differs according to age and the number of doses required, you can get vaccinated starting on the date assigned to your group.

The biggest change during the 2026–2027 season is that eligibility for free vaccination for children has expanded from through age 13 to through age 14.

Children from 6 months through 14 years of age, pregnant women, and adults aged 65 and older can receive free vaccination during the designated periods at participating medical institutions or public health centers nationwide.

Even if you missed the recommended timing, you may still consider getting vaccinated later as long as flu season has not ended.

You can make the process more convenient by checking your family members' birth years and vaccination start dates in advance, as well as confirming vaccine availability at the medical institution before visiting.