Why do terminated employees need to be added to the plan?

Terminated employees with a balance in the 401(k) plan from a prior provider must be added to the Betterment plan to help ensure their funds remain invested. Depending on the plan design, they may keep their balance in the plan until retirement or request a distribution. To reinvest their funds in the market, they need a Betterment account. Once the plan exits blackout, they have the option to request a termination distribution if they wish to withdraw their funds.  Please make sure you are including relevant vesting information when porting over terminated employee information to Betterment to help for future distribution requests.