Efforts towards decarbonizing the energy system have to focus on individual actors within the system. Their current and potential future stake in energy consumption and contribution to climate change has to be analyzed when formulating energy policies targeting system-wide reduction efforts. Focusing on firms, this paper develops a framework for the assessment of corporate carbon performance. We use this framework for an empirical assessment of the 100 largest US electricity producers within three different carbon scenarios. Our results show that in a scenario without changes in the US institutional environment electricity producers will not face a severe increase of their carbon exposure and only a small improvement regarding the carbon intensity of the electricity mix is achieved. In a scenario with more carbon-constrained US energy market conditions some companies face a financial risk from using and emitting carbon that more than triples compared to today. However, in a scenario with strong investments in renewable energy technologies the carbon dependency of electricity production can be significantly reduced. We discuss these findings from a climate policy and financial markets perspective.