The present embodiments relate generally to systems and methods for measuring an analyte in a host. More particularly, the present embodiments provide sensor applicators and methods of use with activation that implant the sensor, withdraw the insertion needle, engage the transmitter with the housing, and disengage the applicator from the housing. Systems and methods according to present principles allow for such steps to occur without significant loss of spring force, and without deleterious effects such as seal slingshotting.