I’m not sure about a phone “interview”, but HR did do what I would call a brief phone screen before I got scheduled for the formal interview. It was basically are you still interested, what offices would you be interested in (they told me which of those had openings), how soon would you be available to report to duty if hired, etc. They also asked to verify my resume was current and my list of references. I believe they also told me what grades I had qualified for and asked which I’d be willing to accept. Once I answered all those questions, they immediately scheduled a formal interview date.

For the record, this all took place in Oct 2017, so things may very well have changed slightly since then.

Feel free to PM me if you want anymore details on any part of the process. And good luck!