Vanguard research shows that auto-enrollment has on average doubled the number of employees who participate retirement plans for employers who offer it to their workforce, and Unum has seen similar success among its own clients. Some of the most successful employers include warehouse club with 70,000 employees had 95 percent employee participation; a 2,000-employee manufacturer had an 83 percent participation rate; and a 400-employee auto dealership that saw participation reach 80 percent.

The same model could be used to increase participation rates in disability coverage, Unum contends. The need certainly exists, says the disability insurer: a 2017 American Payroll Association survey found that 71 percent of Americans would find it somewhat or very difficult to meet current financial obligations if their paycheck were delayed by one week. And it's not just baby boomers who are worried: One in four millennials aged 20 can expect to be out of work for at least a year because of a disabling condition before they reach the normal retirement age, according to the Social Security Administration.

A 2012 report by Unum and the Consumer Federation of America found that 88 percent of Americans think employers should offer disability insurance that could help protect their finances if they were unable to earn a paycheck due to sickness or injury. Fifty-six percent of workers would even pay the full premium.

Still, a LIMRA report found that only 26 percent of workers actually sign up — which is why auto-enrollment is a smart choice, Unum asserts.

Employers can also boost disability coverage participation by taking an active approach, Unum says. With active enrollment, employees must respond with a yes or no to all benefits being made available. “This leads to higher participation rates and provides employers an opportunity to inform their employees of new policies or coverage plans,” Unum writes. “It also helps employees ensure their coverage matches their current family situation and needs for the year.”