An indicator suitable for signaling restricted flow of a fluid through a filter mounted in a filter assembly includes a housing having an inner cavity. A diaphragm disposed within the housing separates the inner cavity into first and second chambers and deflects from a neutral position in response to applied pressures within the first and second chambers. A tab assembly opposite the diaphragm includes a spring-loaded flag moveable from a first position within the housing to a second position outside the housing. A pin operably coupled to the diaphragm holds the spring-loaded flag within the housing when the diaphragm is in the neutral position. In response to the diaphragm being deflected sufficiently from the neutral position to release the pin, the spring-loaded flag travels to the second position outside the housing, thereby indicating a restricted flow condition for the filter.