Freedom of choice enhances the sense of agency over the outcomes of our actions and has been suggested to benefit experiential learning. Yet, how agency experience influences the neurophysiological processing of feedback during goal-directed behavior is not clearly understood. We performed two EEG studies to examine how freedom of choice influences feedback processing during reinforcement learning. Participants received performance feedback in form of monetary gains and losses following binary item choices by the self or the computer. Study 1 (N = 30) revealed augmented feedback-induced midfrontal theta power for free compared to forced choices, irrespective of feedback valence, suggesting enhanced performance monitoring for self-determined actions. Study 2 (N = 37) additionally demonstrated that freedom of choice increases feedback-related ERPs, indicating wide-ranging and robust effects of choice on neural outcome processing. Free compared to forced choices elicited a larger N100, reflecting intensified sensory feedback processing. In addition, only self-determined action outcomes elicited a Reward Positivity, indicating a selective differentiation of positive and negative feedback for self-determined actions. Interestingly, Study 2 also points towards a stronger impact of choice on midfrontal theta power for negative feedback. Crucially, our results suggest that the neuronal impact of affective feedback is specifically associated with freedom of choice, rather than learning differences between free and forced choices. Intensified processing of affective feedback when having the freedom to choose between different response options might constitute a functional mechanism facilitating goal attainment when experiencing a high sense of agency.