In this paper, a self-testable SiGe low noise amplifier (LNA) is designed and a Built-in-Self-Test (BIST) methodology is proposed for amplifiers embedded in RF systems. In this BIST methodology, the RF amplifier has the capability to simultaneously test multiple performance specifications on-chip, including Gain and P1dB. The self-testable LNA can be placed in a testing mode, in which it self-generates a signature of its health using oscillation principles. It eliminates the requirement of any external test stimulus for testing purposes, thus enables the possibility of self-testable RF designs. For the proof of concept, the presented SiGe LNA is designed to operate in the X-band (9.0 GHz) in a commercially-available 6 metal layer, 0.18 µm, 120 GHz SiGe BiCMOS platform. This self-testing design concept can be extended to CMOS amplifiers as well. Furthermore, in this paper, the built-in-self-test methodology is demonstrated using board-level as well as chip-level prototypes.