Late Tuesday night, Supreme Court Justice Sonia Sotomayor temporarily blocked a key requirement about birth control.
Sotomayor exempted two Catholic non-profits from having to provide contraception coverage to its employees.
One of those groups is the "Little Sisters of the Poor," a group of nuns that operate "Saint Anne's Home" in San Francisco.
"They are saying that the Affordable Care Act infringes on their religious liberty by forcing them to buy birth control that conflicts with their religion and that's where it begins and ends for a lot of these religious groups," said Eric Marrapodi, co-editor of CNN's Belief Blog.
The Obama administration has until Friday morning to respond to Sotamayor's order. After that she will decide whether to extend it.
Meanwhile, the Obama administration says 2.1 million people signed up for health coverage beginning Wednesday.