I took a xanax (alprazolam) .25 on sunday night.. will it still be in my urine today ?

Xanax (alprazolam): Xanax (alprazolam) has a half life of 12 hours. It takes about a week for it to be undetectable on urine drug screen.

It depends on your: individual excretion rate. According to data half life varies from 11 to nearly 20 hours. After 5 half lives (2.3 days) at 11 hours half life, you would still have about 3% of the drug in your system so it could show up. Was this not your prescription? If it was your drug you have nothing to worry about, if you took a friend's medication and got drug tested you could have a problem.