A TB test usually does not have one universal expiration date; for many workplaces or programs, a negative skin test or blood test is treated as valid for about 1 year , but the exact rule depends on who is asking for it and your risk level.

Quick Scoop

  • Skin test (PPD/TST): often accepted for 1 year in employment or screening settings.
  • Blood test (IGRA): often accepted for 1 year as well in those same kinds of settings.
  • Chest X-ray: some programs accept it for 5 years instead of repeating testing.
  • Healthcare settings: routine annual testing is generally not recommended unless there was an exposure or ongoing transmission.

What matters most

The answer depends on the reason you need the test. An employer, school, shelter, travel program, or clinic can each set different rules, so a “good for” date is really a policy question, not a medical one.

Simple rule of thumb

If you need a TB test for paperwork, the safest assumption is that it may need to be recent , often within the last year, and sometimes much sooner depending on the form or workplace. If there was a known exposure, repeat testing may be needed sooner, such as 8 to 10 weeks after exposure in healthcare guidance.

Tiny example

If a job asks for “current TB clearance,” a negative result from last year might be fine in one place but not enough in another. The form’s wording is what decides it.

Bottom line

For most people, a TB test is “good for” about a year in common screening and employment contexts, but there is no single universal expiry date.