The Trump administration scrapped 14 pages of Affordable Care Act information from its Medicaid website in a move that could make it harder for enrollees to find out the landmark law’s effects on their benefits, according to the Sunlight Foundation’s Web Integrity Project.

The changes brought to light July 12 drew criticism from a top Democratic lawmaker, who saw the decision as part of a Republican effort to undermine Obamacare through regulations and other changes. Most recently the Trump administration...