Accelerators assist early-stage ventures by offering networking opportunities, access to funding and training. We map business accelerators in five categories: Independent Accelerators (IA), Corporate Accelerators (CA), Hybrid Accelerators (HA), University Accelerators (UA), and Government Accelerators (GA). We argue that accelerators can be described by two main acceleration models (Model 1 and Model 2), providing accelerators with valuable information on how to position themselves strategically in the ecosystem. We identify a list of accelerators’ ‘characterizing’ variables that allows for differentiating the five accelerator categories and describing the various acceleration models. Empirical evidence is provided on the two acceleration models based on a case study of eight Swiss acceleration programs.