[Someone]

Not typically, always. “Ballistic” in “ballistic missile” means “moving under the force of gravity only”

[elil17]

Might you not use some fuel for countermeasures during the midcourse phase?

[tomatotomato37]

Yeah, a ballistic missile's bus still does a lot of horizontal maneuvering during the mid-course phase to actually get on target; the main boost phase is mainly just for getting it pointed in the general direction and proving verticality