Interim testing of studied information, compared with restudying or no treatment, facilitates subsequent learning and retention of new information--"the forward testing effect." Previous research exploring this effect has shown that interim testing of studied information from a given domain enhances subsequent learning and retention of new information within the same domain. In the current research, we ask whether interim testing can enhance subsequent encoding and retention of new information from a different domain. Experiment 1 showed that the forward testing effect is transferable; Experiment 2 further demonstrated this transferability even when material types and test formats are frequently switched; Experiment 3 documented transferability from low- to high-level learning. The results support a combined test-expectancy and retrieval-effort theory to account for the transfer of the forward testing effect.