QMED Testing

I am looking into a job where I was told to take me QMED test, then apply. If I am hired I can then get my QMED needed sea time when working until I actually qualify for the QMED. Can this be done. I thought I was told in the past that I can not take a test until I have the qualifying seatime. Can I take the test with out the sea time or do I need the sea time first?