The US Department of Transportation (DOT) has denied an exemption request filed jointly by JetBlue Airways (B6, New York JFK) and Spirit Airlines (NK, Fort Lauderdale International) that would allow them to operate under common ownership, saying this would be premature pending the outcome of a lawsuit by the Department of Justice (DOJ) to block the proposed merger between the airlines.

The Department found the denial was warranted in light of an executive order by US President Joe Biden in July 2021, which requires both departments to coordinate their efforts to preserve competition. Its decision was also informed by the DOJ's conclusion that the proposed merger would have anti-competitive effects, and the pending federal lawsuit challenging the legality of the transaction. "Should the present facts and circumstances change, the joint applicants may file a new application at that time," it stated.

On March 7, 2023, the DOJ, along with the Attorney-Generals of the Commonwealth of Massachusetts, the District of Colombia, and the State of New York, filed suit in the US District Court in Boston challenging the proposed merger, alleging it violates Section 7 of the antitrust Clayton Act. It claims the merger would eliminate competition, lead to higher ticket prices and reduced passenger capacity, result in fewer consumer choices, and facilitate increased coordination among JetBlue and its remaining competitors. The trial has been scheduled for October 16, 2023.

In support of their application filed on February 9, 2023, the airlines stated they would remain separate entities and brands following their planned merger's consummation. They also argued that granting the exemption would be consistent with the DOT's past practice.

JetBlue and Spirit, both Delaware corporations, each hold certificates of public convenience and necessity authorising them to operate interstate and foreign scheduled air transport of persons, property, and mail, as well as various certifications, exemptions, and other economic authorities from the regulator authorising foreign scheduled flights. JetBlue currently operates domestically and to 26 countries, while Spirit provides domestic flights and serves 15 countries.