With more than 62,000 plans, Paychex is the record-keeper for approximately one out of every 10 401(k) plans in the United States.

That makes it an undisputed market leader. Over the past year or so, however, Paychex has made a big push for an even larger share of the market, taking advantage of new regulations that opened the door for companies to enter the financial advisory services world.

The publicly traded Rochester, N.Y.-based payroll giant has begun partnering with advisors, a move that it says has, indeed, allowed it to capture even more of the medium-size plan market, accounts with $2 million to $10 million in assets.