Background seems widespread. I don't know about drug testing. I didn't need one, but I just assume they could ask at anytime if the wanted or suspected something, especially in clinical years. Every school has immunization requirements. But from what I gather, it varies. TB testing is a big one. I had to start with a two-step the we are required to be tested every year, without a lapse. Check with your school. We had a list/form we had to cover. And titers for immunizations too. Health exam too.