Deck 4 of the Texas Medical Association's "Hey Doc" campaign: Who Can Enroll in the Marketplace? Physicians are Americans’ most trusted source for information on the Affordable Care Act (ACA), according to a new national poll; but people are not turning to their doctors to learn about it. The Texas Medical Association is about to change all of that. TMA’s “Hey, Doc” education campaign will provide objective and nonpartisan answers to the most frequently asked questions about the new ACA health insurance marketplace. We want to make sure all Texans understand what the marketplace does and what steps they need to take.