Tuberculosis screening is the single most common reason an immigration medical exam takes longer than expected. As of October 2018, USCIS requires the Interferon-Gamma Release Assay (IGRA) blood test — not the older Mantoux (TB skin test) — for everyone aged 2 and older.
The IGRA blood test
One blood draw, results in 24–72 hours from the lab. No follow-up visit needed if your IGRA is negative.
What if my IGRA is positive?
A positive IGRA does NOT mean you have active TB. You’ll be referred for a chest X-ray to rule out active disease. If the chest X-ray is clean, you may be diagnosed with latent TB infection (LTBI). USCIS does not bar admissibility for LTBI alone, but you’ll be referred to your local health department for follow-up.
What if my chest X-ray is abnormal?
If both the IGRA and the chest X-ray suggest active TB, you’ll need a sputum culture before USCIS will accept your I-693. Active TB is a Class A condition (inadmissible) until treated.
More detail on how we handle this step of the visit is on our TB screening service page.