The Republican lawsuit targets reinsurance that helps insurance companies provide universal coverage without accounting for pre-existing conditions.
The White House, on the defensive over the latest Obamacare delay, deflected criticism Thursday about President Obama's unilateral actions and accused Republicans of providing no serious alternative to the Affordable Care Act.
"You know they want to repeal the Affordable Care Act -- they don't want to fix it," White House press secretary Jay Carney said when asked why unilateral delays of the law, but not GOP legislation, were acceptable.
Carney said that while the administration was working to expand access to health care, Republicans were "voting for the 50th time to repeal the Affordable Care Act without an alternative."
One day earlier, the Obama administration said it would allow insurers to issue until October 2016 health plans that do not meet Obamacare regulations. The move was an attempt to further limit blowback from Obama's broken promise that all Americans could keep their health plans if they wanted to.
Carney framed the new delay as a way to grant individuals flexibility to find the insurance plan that best fits their needs. But Republicans counter that the White House is trying to protect vulnerable Democrats seeking re-election in November.
Wednesday's extension comes after the administration delayed the employer mandate for midsize businesses -- for a second time -- and a series of other delays for central Obamacare provisions.