This document is about an examination of how employers' automatic enrollment policies influence longer-run participation and contribution status in defined contribution retirement plans among older Americans. The study uses data from the Health and Retirement Study to compare demographic, financial, and health characteristics between those who choose to opt out of a plan with automatic enrollment, those who choose not to participate under voluntary enrollment policies, and those who actively participate. The authors find large differences in characteristics between participants and non-participants, but relatively little differences across enrollment regimes when conditioning on participation decisions.