How long will Tylenol 3 stay in your system in a drug test?

Tylenol 3 contains codeine phosphate - a controlled substance. It will be picked up on a drug test.

You don't fail drug tests if they detect a controlled substance that is part of a medicine that a doctor has prescribed for you.

If you have a prescription for it, you don't fail the drug test. If you don't have a prescription for it, you will fail the drug test.

There is one caveat: there are jobs that you are not allowed to do while taking certain medications because the medication will interfere with your ability to do the job properly/safely. If you were violating those rules by working while medicated you would fail the drug test on that basis. Codeine phosphate is typically one of those medications.