Transition transport models for the prediction of laminar-turbulent transition in numerical simulations have reached some maturity for applications with natural laminar flow. However, little is known about the applicability of these models to cases with boundary-layer suction. This work demonstrates that the state-of-the-art transition transport models are not suited to capture the effect of suction on laminar-turbulent transition. Therefore, new modeling approaches are presented and discussed. Simulation results with the proposed modifications for the DLR \(\gamma \) model are assessed based on the numerical test case of an ideal flat plate. Furthermore, experimental data of a flat plate in the DNW-NWB wind tunnel is considered as a reference.