This study discusses the content of participation required in each stage of the service customer participation process, focusing on pre-encounter participation and encounter participation. Among various customer participation behaviors, this study attempted to identify forms of participation that can negatively affect interactions with employees and to measure their effects. Additionally, the effects of each customer participation-related variable were compared across two service types differing in their level of dependence on the service provider, thereby conducting an integrated examination of the stage-specific effects of customer participation and the differences by service type. The results showed that customers' pre-encounter participation (pre-encounter proactiveness) had a positive effect on communication, rapport, and compliance at the service encounter, while reducing proactiveness at the encounter. This can be interpreted as follows: by learning in advance what role is required as a partial employee before using the service and what knowledge is needed for service utilization, the quality of communication at the encounter improves, while negative behaviors such as unnecessary demands are mitigated. Additional verification was conducted on differences according to the level of dependence on the service provider. As noted in the empirical analysis, the effects of pre-encounter proactiveness on customer participation at the encounter (rapport, communication, compliance, and proactiveness) were stronger when dependence on the service provider was high. Moreover, the effects of communication and proactiveness—which can manifest as negative forms of customer participation—on encounter employees' stress were found to be relatively weaker when the level of dependence on the service provider was high. Finally, the difference in the effects of communication and proactiveness on employee stress was analyzed according to the level of customers' pre-encounter proactiveness. The results showed that while the difference was not significant for communication, for proactiveness, the effect was greater when customers' pre-encounter proactiveness level was low. This study suggests that pre-encounter participation and the level of dependence on the service provider can exert diverse influences on customer participation behavior at the encounter, and by elucidating these findings, strategic recommendations can be made for service firms seeking to induce positive customer participation behavior and improve service quality.