Despite the progress that has been made in modeling failure in composite materials, predicting high-cycle fatigue in composite laminates remains an open challenge. In this contribution, we present a micromechanical model for fatigue crack growth. Extending recent work related to microscale modeling of creep rupture [1], damage due to cyclic loading is included following the cohesive fatigue model by Dávila [2]. A representative volume element with random fiber distribution is used with the Eindhoven Glassy Polymer model [3] for the thermoplastic matrix. A customized loading scheme is used where complete loading cycles are resolved intermittently, while the fatigue damage evolution is performed in an envelope approach. The resolved cycles are needed for evaluating the time-dependent plasticity model, and provide information on the evolving local stress ratio as required for the cohesive fatigue model. For the evolution of plasticity, a time-homogenization approach is adopted [4]. Model results are compared with experimental observations from off-axis tests on unidirectional carbon/PEEK. It is demonstrated that the model can reproduce the experimentally observed transition from crack-growth-dominated fatigue failure to plasticity-dominated creep rupture. REFERENCES [1] D Kovačević, BK Sundararajan, and FP van der Meer. Micromechanical model for off-axis creep rupture in unidirectional composites undergoing finite strains. Compos Part A, 176:107860, 2024. [2] CG Dávila. From S-N to the Paris law with a new mixed-mode cohesive fatigue model for delamination in composites. Theor Appl Frac Mech, 106:102499, 2020. [3] LCA Van Breemen, ETJ Klompen, LE Govaert, and HEH Meijer. Extending the EGP constitutive model for polymer glasses to multiple relaxation times. J Mech Phy Solids, 59:2191–2207, 2011. [4] IBCM Rocha, FP van der Meer, and LJ Sluys. Efficient micromechanical analysis of fiber-reinforced composites subjected to cyclic loading through time homogenization and reduced-order modeling. Comput Method Appl Mech Eng, 345:644–670, 2019.