Mutualism is reviving again in several countries, replying to state and market failure with an alternative, social insurance setup. We study participation in such new mutuals with a focus on embeddedness. We distinguish group-level embeddedness (network structure) and individual embeddedness (the type and quantity of ties to other group members) and study how these relate to members’ commitment to mutuals and their trust in the commitment of others. We show that group-level embeddedness primarily affects trust, while individual embeddedness more strongly associates with commitment. We reveal these dynamics for mutuals of different ages using a unique multilevel dataset on the motivations, beliefs and social relations of more than 5000 members of 230 small Dutch mutuals. Our results highlight the importance of thinking critically about the levels at which social embeddedness plays a role, as the dynamics are more subtle and not all means of embeddedness are equally fruitful.