The timing of fat transfer can be done either before, during or after a surgical procedure. I typically perform fat transfer at the same times as a facelift to help minimize any future downtime. Once a facelift has been performed, it may ideal to wait 3 to 6 months before doing fat tranfer to ensure that there is no residual swelling.
If the transfer wasn't performed during the same time as the lift, then I like to wait approximately 3 months. Fat transfer to the face is a perfect compliment to the facelift because it restores volume loss that a lift doesn't provide.