An autoinjector includes a case adapted to hold a medicament container having a needle telescopically coupled to the case and movable between a first extended position relative to the case in which the needle is covered and a retracted position relative to the case in which the needle is exposed. The autoinjector includes a plunger rotationally and slidably disposed in the case rotatable relative to the case between a first rotational position in which the plunger is engaged to the case and a second rotational position in which the plunger disengages the case engages the plunger to rotate the plunger from the first rotational position to the second rotational position when the needle shroud translates from the first extended position to the retracted position. The autoinjector includes a cap removably coupled to the case includes at least one compliant case beam adapted to releasably engage at least one aperture in the case.
