Rubio said on NBC's "Meet the Press" Romney's pro-life credentials were never in doubt but he was also in favor of exceptions.
"He is pro-life and he has talked about how he's pro-life," Rubio said. "He also believes in certain exceptions."
Rubio said Romney took issue with the Obama administration insisting the Catholic Church include contraception in their employee health insurance plans and opposed "Washington bureaucrats" dictating terms to employers.
At the same time, Romney favored exemptions only to companies and entities with long and established moral objections to contraception. Companies offering "fake" objections just to save money were not likely to obtain such exemptions, Rubio said.
"It has to be a real objection," Rubio said. "Certainly if they were faking the objection, I think they would be pilloried in public -- in public coverage of it."