The Trump administration proposed a rule Monday that would require hospitals to post online the health-care prices they have negotiated with insurers, about a month after President Trump signed an executive order aiming to give Americans more information about the cost of health services.

Health insurers and providers have fiercely opposed having to publicly reveal their negotiated prices, which they say would stifle competition. Yet the Trump administration has argued that forcing hospitals to post their prices will allow consumers to make more-informed choices about where to get care and in turn help lower their health-care costs.

Trump has said he is eager to make health care a central plank of his 2020 reelection bid, as voters consistently cite high costs as one of their top concerns. Trump’s June executive order laid out priorities for the Department of Health and Human Services and other agencies in crafting rules to address secrecy in health-care prices. […]