Target-date funds could be the next financial product subject to federal scrutiny. A Senate committee recently identified three main concerns with the product, the Wall Street Journal reports: lack of disclosure and consistency in their design; excessive fees; and conflicts of interest.

At a hearing Wednesday, Sen. Herb Kohl suggested greater oversight for what he said could become the “No. 1 savings vehicle in America.”

From the Journal: “While witnesses generally praised target-date funds as an important option for retirement savers, they also raised numerous concerns. Phyllis Borzi, assistant secretary of labor, said that differences in target-date funds and associated differences in their performance have prompted questions about whether fiduciaries and workers understand their benefits, risks and costs.”

As such, the Labor Department is examining regulations that determining eligible default options, as well as looking for ways to help plan fiduciaries select and monitor funds.