This July, Oregon will become the first state to offer a retirement plan to part- and full-time private-sector workers who don't have access to one through their employer. The program is ultimately expected to cover nearly one million workers in the state.

Six other states -- California, Connecticut, Illinois, Maryland, New Jersey and Washington -- are also planning to roll out similar programs within the next five years. When that happens, the seven states will cover nearly one-quarter of the nation's private-sector workers without an employer-sponsored retirement plan.

Called Secure Choice, these programs have been catching on since California in 2012 decided to study the feasibility of creating one. They aren't pensions but instead independently managed and pooled retirement accounts. The programs pay for themselves through fees, so states aren't liable for the cost. In addition to the seven states that have approved a program, at least eight other states -- including populous New York -- have or are considering legislation to launch their own.