CareCredit's staff offers consumers personal lines of credit for health-care services. CFPB said there are about 4 million active CareCredit cardholders.

The CFPB said about 85% of CareCredit borrowers have been put on a “no interest if paid in full” plan allowing them to make monthly payments while CareCredit assessed 26.99% annual interest on the consumer's balance throughout a promotional period of six to 24 months.

“If any portion of the balance has not been paid when the promotional period ends, the consumer becomes liable for all of the accrued interest,” said the CFPB.

The bureau's order said consumers who signed for the credit card received an inadequate explanation of its terms, causing them to incur a significant amount of debt.

“Medical debt is already a big problem for many Americans. Poor credit card transparency should not be making the problem even worse,” CFPB Director Richard Cordray said.

“Deferred-interest products can be risky for consumers in the best of circumstances, and today's action ensures that CareCredit will no longer profit from consumer confusion. The Bureau will not tolerate financial companies that take advantage of patients and their loved ones,” Cordray said.

Cordray addressed the enforcement action during a press call on Tuesday but did not take questions from reporters.

CareCredit must set up a reimbursement fund and allow consumers to file a claim, said Cordray. An independent adjudicator will administer the program.

Deputy Enforcement Director Anthony Alexis said GE Capital is going to be responsible for sending out notices to consumers eligible for reimbursement under the program.