The IRS broadened the choices available to cash-balance plan sponsors in setting their interest crediting rates. For example, sponsors that use a fixed rate in their plans will be allowed to set the rate as high 6 percent, rather than 5 percent.

Participants in particular should welcome the news because, regardless of the rate of return actually earned on the assets in a cash-balance plan, their accounts are credited at the specified rate each year.

The new rules also give sponsors the option of multiple investment strategies within a single plan. For example, a plan sponsor could use a more conservative portfolio for longer-term employees and a different strategy for other groups of employees.

"It was a strong endorsement of cash-balance plans," Sansone said of the IRS regulation.

Actually, there was plenty of reason to consider a cash-balance plan even before the IRS acted. While such plans still represent just a small slice of the retirement pie, they're growing faster than all other account types, including 401(k)s.

Of course, there are about 513,000 401(k)s in the United States, so this really is an apples-to-oranges comparison. Still, there were 9,648 cash-balance plans active in 2012 compared to 7,926 in 2011. That's a 22 percent increase. By comparison, the number of 401(k)s grew by 1 percent in the same period.

Oh, and here's one more number that caught my eye: the assets in these plans is approaching $1 trillion, which ain't chopped liver, right?

Sansone, for one, believes cash-balance plans should continue to see solid growth for the foreseeable future.

And that's why you'll hear him say things like, "We're really still on the front end of this wave."

Sansone, who works for the actuarial and retirement-plan design firm Kravitz Inc., is at CFDD in hopes of getting more advisors to join him in riding that wave.

His first challenge, however, simply might be assuring them the water's fine. Which helps explain his presentation: "The Fastest-Growing Retirement Plan You Never Heard Of: Driving Growth with Cash Balance Plans." 

For the uninitiated, a cash-balance plan is a super-charged DB plan with a few features borrowed from the 401(k).

Like a traditional pension, a cash-balance plan specifies an annual employer contribution for each participant. A flat amount or a percentage of a participant's salary is placed in the plan each year, along with the interest rate. Notably, a cash-balance plan is portable, just like the money in a 401(k). Participants also can roll their accounts over to an IRA when leaving a company or retiring. Unlike a DC plan, participants do not make investment choices.

Sansone believes demand for cash-balance plans will climb as tax rates rise and as people, especially high earners, realize they need to do a better job of retirement preparation.

Cash-balance plans can be especially attractive for law firm partners or some other kind of professional services firm or, really, any business owner or partner who's taken their $52,000 tax deduction after maxing out their profit-sharing plan contribution. That's what makes these plans so super-charged.

According to Kravitz's contribution limits tables, a 60-year-old with a cash-balance plan can contribute an additional $217,000 to their retirement. And that can mean a tax savings of more than $100,000.

That's why, Sansone said, he hopes more CPAs will become aware of cash-balance accounts. Plan advisors, of course, also have yet to get their hands around cash-balance plans in any significant numbers.

Sansone faces a couple of other headwinds in making his pitch – including the fact that these plans generally require several years of consistent contributions and, because assets are pooled, they're not self-directed.

"Sometimes, people can't look that far out and sometimes owners really want to have control of those assets," he said.

On the other hand, as Sansone said, a participant in a cash-balance plan can squeeze 20 years of savings into 10.

And that's saying a lot.

Want to know more? The Department of Labor has an FAQs page about cash-balance plans that can be found by clicking here.