Be honest. When was the last time you updated your401k plan design? Five years? 10Years? 20 Years? Never?

And I'm not talking about rearranging the investment options inyour plan menu, I'm talking about the infrastructure of the planitself.

You know what I mean. Things like your matching strategy, your loan policy,and, yes, even the very framework (i.e., not necessarily the actualinvestment options) of your investment menu.

If the last time you looked at your plan design the nation was consumedwith the debate of what “is” is, then your 401k plan may be due fora major overhaul.

Plenty has changed over the last couple of decades, and we'vecome to discover which plan design elements are stale and whichnewly discovered plan design elements seem to be the new standard,(see “The Best and the Worst of 401k Plan DesignElements,” FiduciaryNews.com, October 27, 2015).

We're all aware of the need to update plan documents on aperiodic basis whenever laws or regulations change.

In fact, the IRS has an on-line document titles “A Plan Sponsor's Responsibilities” thatincludes the following direction to plan sponsors: “Review the plandocument for law changes and update it as necessary.”

These aren't the kind of updates I'm referring to.

Rather, the DOL's on-line document “Meeting Your Fiduciary Responsibilities,” comescloser to my intent when it states “Employers will want to befamiliar with their plan document,… and periodically review thedocument to make sure it remains current.”

“Remaining current” definitely applies to legal and regulatorychanges, but – and this is what I want to emphasize–it furthersuggests a sense of staying up-to-date with commonly accepted “bestpractices.”

The term “best practices” is often overused. One thing is clear,though – when it comes to 401k plan design elements, best practicesis an evolving concept, a “moveable feast” of ideas that ebb andflow in popularity.

Remember when “best practices” meant three investment options,one for stocks, one for bonds, and one for cash?

That quickly melted away into the Morningstar style boxapproach.

Today, many of the statistics-based artifacts of ModernPortfolio Theory like the style box have fallen by the wayside,having been replaced by empirically driven behavioral models.

Or how about employer matching strategies?

In the beginning, we saw a simple dollar-for-dollar match. Thisgave way to the percentage match.

In turn, behavioral finance studies moved plan sponsors towardsthe gradual adoption of the staggered percentage match–either byspreading out a smaller match over a larger deferral range orsimply moving the match to high deferral rates.

The IRS certainly hasn't changed its rules on these matters.

Indeed, the IRS wouldn't touch the investment menu with aten-foot pole, save for the most generic of comments.

Even the DOL, which has a history of promotingout-of-date investment memes, has ceded the leading edge to theworld of academia.

Regulators, at their best, focus only on making sure the plansponsor makes good on its promise–whatever that promise mightbe.

The precise nuts and bolts of plan design, therefore, restsquarely on the shoulders of the plan sponsor. And you know whatthat means.

That means it's often up to the plan's service provider to bringthe plan sponsor up to speed when it comes to the “best practices”of 401k plan design elements.

And that means revisiting the plan every few years to insurethose best practices are properly incorporated.