A medical injector is provided herein having a body and a needle mounting surface movable relative to the body, the needle mounting surface having features for mounting a needle thereto. In an initial state, the needle mounting surface is disposed within the body with no needle mounted thereto. With relative movement between the body and the needle mounting surface, the needle mounting surface is urged out of the body. Advantageously, a medical injector is provided which ensures proper sequence in preparation of the device, particularly with respect to the step of allowing mounting of a medical needle to the device subsequent to preparation of the medicament to be administered.