Despite an uncertain tax and regulatory environment, retirement plan sponsors are not shying away from the added expense of hiring third party administrators to help manage their 401(k) and 403(b) retirement plans. If anything, TPAs are more popular than ever because they help companies better navigate the murky, and sometimes choppy, regulatory waters.

"It is an interesting time for them. A lot fear that fee transparency will equal pressure on fees, that once plan sponsors get this fee information from providers they may shop around and pick the cheapest plan provider out there," said Ary Rosenbaum, managing attorney with The Rosenbaum Law Firm in New York. "I don't think that will be the case. TPAs still offer great value as a service provider. Not all TPAs are equal. Some are better than others, but TPAs need to do better marketing for themselves to tell plan sponsors why they are better than their competitors, why their service is better."

 TPAs offer a tremendous value when it comes to administration, recordkeeping, discrimination and compliance tests and anything that is very technical, he said.