Every appointment and every promotion every officer in the military receives has to be approved by the Senate. Most appointment list and promotions are simply approved by the Senate. Occasionally, some jamoke, that Senator Levin, will block an appointment as he did a couple of weeks ago preventing the Vice Director of the Defense Information Systems Agency from being promoted to Vice Admiral and becoming the director of that Agency.
It appears that Congress has passed legislation requiring Senate consent for military appointments. Interesting. I wonder when this occurred.