A test assembly for testing electrical performance of microcircuits contained in leadless packages has Kelvin contacts. Slider contacts in a plurality of contact assemblies slide compliantly to accommodate lack of coplanarity in terminals on the package. A resilient elastomeric block may be inserted through interior spaces of the contact assembly and in interfering relation with features of a housing that supports and aligns the contact assemblies, to apply force to the slider contacts to force them against the microcircuit terminals.