Just a phone call going over experience. Answer their questions regarding your work history and you're good to go. They may go over multiple contracts and go over all the details you need as well.

There was a phone call to set up a phone interview time. The actual interview took about 40 minutes. The gentleman interviewing was very enthusiastic and informative. He actually answered all of my questions I had leading up to the interview by the end, so I didn't have much to ask about.