Pooled Employer Plans (PEPs) are a new variety of an existing structure for retirement plans: Multiple-Employer Plans (MEPs). PEPs have the potential to become an important tool for improving our retirement systems’ coverage and adequacy, particularly for small employers that lack the resources to provide a single-employer plan. In this paper, we take a retrospective look at the challenges and successes of MEPs to support regulators and industry professionals in making PEPs successful.