There's so much bad news on the U.S. retirement front, it's a breath of fresh air to discover an actual upbeat assessment for current and future retirees.

That's exactly what we're getting from a big, five-year study released from Wells Fargo Institutional Retirement and Trust, which tracked five years' worth of retirement savings behavior among the 4 million participants in 401(k) plans administered by Wells Fargo.

The study, entitled the "Driving Plan Health" report, provides fresh evidence that 401(k) participation rates are climbing across all age demographics. "401(k) plan participation has increased by 19% during the last five years, with increases noted across all demographic segments," the study says. "Average contribution rate and participant diversification have also improved during this time span."

But that's just the appetizer: there's other good news for retirees in the report, as well. Here are five key, positive takeaways from the Wells Fargo report that should shake some grit and rust off the U.S. retirement savings landscape and give it a brighter look heading into the second half of 2016:

1. 401(k) plan participation rates are rising - everywhere. "When we looked at participation by generation, Boomers have the highest participation rate, currently at 65.9%," Wells Fargo says in an email to TheStreet. "However, Millennials and Gen X-ers have gained ground in their participation rates over the last five years as well. Most notable is the 32.1% growth in Millennial 401(k) accounts."

2. Contribution rates are up, too. 28% of Millennials are contributing at least 10% to their plan (this includes employee matching contributions) compared to 35% of Gen X-ers and 44% of Boomers hitting this minimum contribution rate, the report states.

3. Asset diversification, strongly touted as an investment necessity, is stronger. "Younger and less tenured employees are more likely to satisfy the minimum goal diversification - either a minimum of two equity funds and a fixed fund, or an asset allocation fund such as a target date fund - in their 401(k)," Wells reports.

4. Better yet, 401(k) savers of all income levels are diversifying their plans. Approximately 82% of participants on the lower end of the income scale (that's "common especially for those just starting out their careers," Wells Fargo says) meet plan diversification goals, while 78% of higher earners fare the same.

5. Roth (after-tax) 401(k) deferrals continue to gain traction. More 401(k) plan savers are factoring in tax diversification strategies by leveraging Roth after-tax 401(k) plan deferrals.

Evidently, U.S retirement savers have done a better job in recent years of educating themselves on retirement savings and investing, and those efforts are starting to produce positive results.

"I'm not surprised at the study's findings" says Carlos B. Arias, senior vice president of investment services at National Care Wealth Management, in New York City. "The biggest change has been the wealth of information now available on investing in general and 401k plans in particular.

While the internet, as a "go to" financial education tool, has been the main progenitor of this increase in knowledge, Arias believes fund companies in general have done a better job of putting information out there about 401(k) plans and the need to start early on the path to securing one's retirement. "It has led to a more educated consumer and investors who are more proactive about investing in their future selves than perhaps past generations," he adds.

More openness by employers and plan sponsors also makes it easier for career professionals to leverage their 401(k) plans.

"Were seeing greater transparency in company retirement plans," says Michael Pruse, a financial planner with Scale Investment Group, in White Lake, Mich. "Fee disclosure regulations have helped somewhat and a renewed focus on retirement plans by the U.S. Department of Labor in their recent 'conflict of interest' fiduciary rule has sparked some investors to pay attention, when they otherwise wouldn't."

"Employers are also responsible, in part, for greater 401(k) participation rates," Pruse adds. "As employers realize what their fiduciary duty entails, more and more are opting to work with advisors who can educate their employees and work with them to find opportunities to save more and invest better."

Still, with so much negative news on U.S. retirement savings habits in recent years, financial industry professionals aren't above saying there's always room for improvement.

"An upgrade in 401(k) plan participant behaviors doesn't mean knowledge and understanding of employer retirement savings plans, or investments in general, is where it should be," says Pruse. "For an illustration of just how far 401(k) investors still need to go, a recent AARP study that finds 71% of plan participants think their plan has no cost to them - but as almost anyone can tell you, there is no such thing as a free lunch."

That may be true, but at least the tide seems to be turning toward a more knowledgeable, dedicated, disciplined 401(k) investor in 2016, if the Wells Fargo study is any indication.

And that's a turn for the better, for a retirement saving sector that sure could use the good news.