The plans let insiders profit while leaving retail traders at a disadvantage, the lawmakers said.
The flaws also risk undermining public confidence in markets, they added.
A trio of Democratic Senators called on the Securities and Exchange Commission to overhaul insider trading rules that allegedly put retail investors at a disadvantage.
Sens. Elizabeth Warren, Sherrod Brown, and Chris Van Hollen urged the regulator to review and update policies regarding 10b5-1 plans. The policy allows corporate executives to schedule stock purchases and sales for the purpose of avoiding instances of insider trading. Yet the group of lawmakers suggests executives — particularly those in the health care sector — are misusing the plans for personal profits.