When the Affordable Care Act loses its penalty for not buying insurance about a year from now, Martin said, why not try the Medicare system to encourage people to sign up for health insurance?

People who turn 65 and aren’t covered by employer plans or other insurance will pay a 10 percent penalty for each year they delay enrolling for a Part B plan. A person who waits five years to buy a plan would pay a monthly Part B premium that is 50 percent higher — from then on.

As for the Affordable Care Act’s individual mandate, Martin said, nobody likes to be told what to do, especially something that may cost thousands of dollars a year. Instead, a penalty for late enrollment or requiring a waiting period might encourage people to buy insurance without a mandate and tax penalty.

But Karen Pollitz, a senior fellow at the Kaiser Family Health Foundation, said Medicare Part B’s late enrollment penalty may be a factor, but it works backward, punishing people when they enroll in the plan, not when they decide not to enroll.

That sort of penalty can discourage healthy people from signing up, Pollitz said. Waiting periods also would discourage healthy people from signing up, while sicker people with higher medical costs sign up right away.

“If you have cancer,” Pollitz said, “you pay the penalty.”