Verified answer

short answer: maybe. \if your current MOS is understrength it is SOMETIMES possible to cross over to another equally understrangth MOS.. but not always.

Usually if you have a good retention NCO. Problem is you're likely just trading sh*t for some more sh*t. With rare exceptions like psych ops, linguist, there is a shortage for a good reason, noone wants to do it or stay in it. Being a cook really sucks but they would probably offer you that. Infantry tends to be a shortage one minute and over manned the next.