Baccalaureate/MD Programs are joint programs that guarantee a spot at the medical school if the student in the joint program graduates with a certain academic standard.  You have to apply as a high school student into these programs.  These programs are meant for those high school students who can convince the programs that the medical profession is in their blood.

A few programs that I know of are...

University of Southern California Baccalaureate/MD Program

UCR/UCLA Thomas Haider Program in Biomedical Sciences

University of Florida Baccalaureate/MD Program