If you are preparing for your green card medical exam, the vaccination section of Form I-693 is often the part that causes the most worry. Maybe your childhood records are in another country, written in another language, or simply gone. Before you assume you have to repeat every vaccine series from the beginning, it helps to know that there is sometimes another option: a titer test.

What a titer test actually is

A titer is a blood test that measures antibodies your immune system has already made against a specific disease. Those antibodies can come from a past vaccine or from having had the illness itself. When the result shows enough antibodies, it is laboratory evidence that you are already immune — which, for certain vaccines, can stand in for paperwork you no longer have.

It is one blood draw, not a series of shots. Several diseases can usually be checked from the same sample.

What USCIS needs from your exam

Your immigration medical exam must be completed by a USCIS-designated civil surgeon, who records your vaccination status on Form I-693. The vaccines you need depend on your age, and the rules civil surgeons follow come from the CDC’s Technical Instructions for civil surgeons.

Those same instructions decide which vaccines can be satisfied by a blood test showing immunity. For some requirements — for example measles, mumps, rubella, varicella (chickenpox) and hepatitis B — a positive titer can serve as proof. For others, a titer is not accepted, and only a documented vaccine dose counts. Your civil surgeon will tell you exactly which of your requirements a titer can cover.

When a titer makes more sense than re-vaccination

A titer is often worth considering when:

  • Your records are missing or incomplete. If you were vaccinated as a child but cannot produce the documents, a titer can show the protection is still there.
  • You had the disease itself. Many adults had chickenpox or measles as children. A blood test can confirm the immunity that illness left behind.
  • A full series would take a long time. Some vaccines are given as several doses spread over weeks or months. A single blood test can be faster than starting a series over.
  • You would rather not repeat shots you have likely already had. If you are already immune, a titer documents that instead of adding doses you do not need.

When re-vaccination is the simpler path

A titer is not always the better choice:

  • If a titer is not accepted for that vaccine, testing will not help — the vaccine dose is what counts.
  • If the result comes back negative or unclear, you will need the vaccine anyway, so you will have done both.
  • If your records clearly show you were never vaccinated, going straight to the vaccine may be quicker.

Each disease is judged separately. A strong result for one does not prove immunity to the others, even when they were given together in one combined vaccine.

How it works at PassQual

At PassQual Health in Miami Gardens, your I-693 exam is performed by Dr. Hendry Pascual, who personally holds the USCIS Civil Surgeon designation. The exam is $190 per person, all-inclusive; the chest X-ray, when it is required, is quoted separately.

Please know before you come in that PassQual does not administer the USCIS vaccine panel on-site. What we do is verify the vaccination records you already have and, where it helps, offer titer testing at an extra cost, which we explain to you before anything is drawn. If you do turn out to need a vaccine, you can receive it elsewhere and bring the documentation back to complete your form.

A few practical tips

  • Bring every record you can find — old vaccination cards, school records, records from your home country, even if they are not in English. Documented doses are always worth showing first.
  • Start early. Lab results and any follow-up vaccines take time, so do not leave the exam until just before your filing deadline.
  • Ask before you decide. Whether a titer or a vaccine is the faster, more sensible route depends on your own records and requirements.

For a fuller explanation of the vaccine requirements themselves, see our guide to USCIS vaccine requirements and titer testing for the I-693.

Have questions first?

Call PassQual Health at 786-677-9922. Questions about your exam are free, and our team can help you understand what your records cover before your appointment.

This article is general information and is not a substitute for advice about your own situation. Your civil surgeon applies the current CDC Technical Instructions to your exam.