Indianapolis-based health insurance provider Anthem recently offered to buy Cigna for $47.5 billion.
Customers can start signing up for the service on Friday.
The health insurance company says hackers accessed information including names, social security numbers, and employment information.
The class-action lawsuit seeks refunds for the alleged inflated premiums.
The insurance company Wellpoint has changed its name to Anthem, which is the company's most-recognizable brand.
A U.S. Department of Health and Human Services official says uninsured Hoosiers are taking time to research the health exchange options available.
The two companies refused to disclose any details of the agreement, but an Indiana University spokesman says it is unlikely to be the last dispute of its kind.
Since Anthem and Premier Healthcare's contract expired, patients have seen a rise in out-of-pocket expenses.
Many IU employees must switch physicians after Anthem and Premier Health Care could not come to a contract agreement.
If no agreement is reached between the two companies by midnight, IU employees could pay more for health services.