And while more than half (54 percent) offer an option to make Roth contributions, less than 11 percent of their employees take advantage of this features.

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The problem, Towers Watson said, is that there's just not enough education in the workplace to help workers understand how to better prepare for the day they leave their jobs.

Sponsors know there's a problem. Only 12 percent of those surveyed said they feel their employees know how much they need to save for retirement, and only 20 percent said their participants are comfortable making investment decisions. 

"Unfortunately, most employers have not yet moved the needle in preparing their workers for a financially secure retirement," said Robyn Credico, the DC practice leader for North America at Towers Watson.

"New plan features alone are not the answer. If employers are to make progress, they must also rely heavily on education and communication so their employees know their options and make informed savings decisions," she said.

According to a LIMRA Secure Retirement Institute study, also released Wednesday, three-quarters of plan sponsors say helping their employees save enough for retirement is one of the top three most important factors in their retirement benefit strategy.

"With more and more employees relying primarily on their defined contribution plan to save for retirement, plan sponsors are recognizing that their decisions can influence their employees' savings habits and ultimately, their retirement readiness," said Kathleen Rook, assistant research director, LIMRA Secure Retirement Institute. 

The survey – based on responses of more than 1,500 plan sponsors in late 2013 and early 2014 – also asked sponsors to grade their retirement plans and their employees' retirement savings habits. 

Most employers gave their own retirement plans a higher grade than their employees' savings habits. More than three-fourths of the plan sponsors gave their company's plan a grade of A or B, but only 61 percent gave their employees' saving habits similar grades.

The Towers Watson survey noted that the majority of employers (61 percent) continue to focus their retirement education programs on traditional, passive methods, including account statements, newsletters, group meetings and online webcasts.

Less than 10 percent use mobile apps extensively or have tried gamification, which uses game design to motivate employees to achieve savings goals. 

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As Towers Watson pointed out, there's a good reason that employers might want to do more to help: An aging population that hasn't saved enough typically means older workers are forced to delay retirement. 

Employees who stick around because they can't retire tend to be less engaged and productive, according to Credico. Their salaries also cost more — in some cases a lot more — than those of younger workers and, of course, they incur greater health care costs.

In other areas, the Towers Watson survey found that while 59 percent of sponsors offer health savings accounts, only 32 percent of eligible employees are taking advantage of them. 

Again, that could be because only 19 percent of sponsors offering HSAs provide education on the various wealth accumulation benefits of HSAs compared to 401(k)s, Towers Watson said. 

That finding was indicative of the larger theme in Towers Watson's survey: participants need more direction from sponsors. 

Most employers said they plan on doing as much; 84 percent said they are prepared to devote more attention to education and communications. 

Sponsors also continue to simplify investment offerings. Two-thirds (66 percent) told Towers Watson they offer between 10 and 19 investment options, and 86 percent use TDFs as their default option. 

But while automatic enrollment continues to gain traction, the survey found that automatic escalation remains underused. 

And while 68 percent of sponsors are offering automatic enrollment to at least some of their workers, few automatically re-enroll non-contributors, and only 35 percent of sponsors with auto enrollment have mandated automatic escalation.

The survey also found that interest is growing in outsourcing investment services. One-third of respondents told Towers Watson they have either already outsourced a lot of their DC work or are interested in delegating all or a portion of their plan oversight.

Also, most companies are requiring participants to pay direct fees. Since 2009, the percentage of companies requiring employees to pay direct recordkeeping fees has risen from 33 percent to 58 percent. Only 23 percent of employers still absorb the cost themselves. 

The Towers Watson 2014 North American Defined Contribution Plan Sponsor Survey was conducted in June and July. It is based on the responses of 457 large and midsize U.S. companies that sponsor a DC plan.

Commentary: What's really feasting on America's retirement readiness