A technique for non-invasively assessing current drawn by a device under test (DUT) by monitoring a supply voltage to the DUT. Frequency data for the DUT may be generated and used to form a current estimation model. First and second voltages are simultaneously measured using first and second test probes electrically connected to the DUT, while the first test probe is connected at a current source, and while the second test probe is connected at a DUT load that is configured to draw current from the current source. The current drawn by the DUT is then assessed by applying the current estimation model to the measured first and second voltages. In one case, the current drawn by the DUT is estimated without insertion of a circuit component into the DUT or extraction of a circuit conductor from the DUT.