We investigate the molecular beam epitaxial growth of GaAsBi and GalnAsBi layers on GaAs and InP-substrates as the materials are intended to serve as an active region in optoelectronic devices. The layers were grown at substrate temperatures between 250-400 degrees C and for all layers the growth rate was kept at a value of 1 ML/s. We show that bismuth incorporation into Ga(In)As is independent of the applied arsenic (As-4) overpressure and can be allocated to different growth domains depending solely on the parameters bismuth flux and substrate temperature, respectively. The maximum bismuth content that could be incorporated was as high as 20.0% in GaAs. (C) 2015 Elsevier B.V. All rights reserved.