Medical needle shield apparatus for covering a needle after use. The medical needle shield apparatus includes a first member, such as, for example, a syringe barrel having a needle mounted therewith. A second member, such as, for example, a shield is mounted with the first member. The shield is movable between a first position whereby the needle is exposed and a second position whereby the needle is covered. A lock is mounted with the barrel such that the shield is slidably movable along an outer surface of the lock. The lock includes a tang that is movable radially outward to fix the shield in the second position.