My front door is out of plane - the top left corner does not sit completely in the frame. The funny thing is this is brand new. We've lived in the house for two years and it just started this winter. That makes me wonder - is this something where I should be readjusting the hinges as is typically the case with out of plane doors, or is this something that's a result of winter weather that will resolve itself in a couple weeks? I don't want to change the hinges and then have it be too tight when the spring comes!
Most units are prehung. If the mortises on the jam and door look perfect and fit precisely, it is usually a prehung. Unless the situation is intolerable, I'd give it a while and let conditions change before making drastic changes to the door or hinge sets. I suspect possible settling or drastic humidity or temperature related expansion to the frame. You should also check to assure all the hung screw are snug. If you have a good 6 foot level, you can compare plumb between the door and frame on both sides to determine if a side has moved or lay the level against the door and look for any bow, gaps etc. An other test is to remove the door (just remove hinge pins) and check that it has not warped by laying it on a known flat surface and look for gaps or rocking indicating that the door may have warped. Sometimes very hard to see a small wain by eye when hung.