A filter assembly for fluid filtration having a push-activated lock and release mechanism. A push filter design activates a floating key lock upon insertion and extraction, where the filter key may be used simultaneously as a lock and as an identifier for particular filter attributes. The filter base may be situated inline, and in fluid communication, with influent and effluent piping, such as within a refrigerator. The filter housing assembly may be attached to, and removed from, the filter base by a push-actuated release. Upon insertion, the filter key shifts the filter lock longitudinally to receive interlocking segments. Upon extraction, the same axial push shifts the filter lock further to align the interlocking fingers within gaps that allow for easy extraction. The specific key lock design allows a user to identify and match certain filter configurations received by the mechanical support, and reject other filter configurations.