For new markets like 5G, Satellite internet, and automotive radar, contactor RF characterization has become more critical. Physical features in the contactor design can drastically change the RF performance. Beyond contactor design, the semiconductor device must be considered as it also has a major impact on RF performance. For instance, the device pinout and signaling type can result in drastically different performance even when using the same contacting technology. This paper will describe the RF parameters critical to defining contactor performance for new 5G, mmWave, automotive radar, WiGig and other high frequency applications. The tools necessary to measure and simulate these critical parameters will be described and finally the critical parameters will then be used to compare RF performance across various pinouts and contacting technologies.