Danica Patrick has confirmed she has a deal in place for this year's Indianapolis 500 that will mark her final competitive outing as a racing driver before hanging up her helmet.

After losing her NASCAR seat with Stewart-Haas Racing at the end of last season, Patrick, 35, announced in November she would be retiring from racing in 2018 following one-off appearances in the Daytona 500 and Indy 500.

Patrick will race for Premium Motorsports in the NASCAR event at Daytona International Speedway later this month, and confirmed to the official Verizon IndyCar Series website that a deal is also now in place for her return to the Indy 500, coming seven years after her last single-seater start.

"I just needed to make sure [the deal] was done. The rest [announcement] I don’t really care about," Patrick said, confirming that no official unveil would come in the near future, but promised it would be "a bigger deal" than her NASCAR confirmation.

"Obviously, the start of this [NASCAR] season didn’t happen any different than last season did, where I showed up and I hadn’t been in the car since Homestead. It’s no different than that.

“But Indy is obviously totally different. We’ll do something a little more substantial for the announcement and the unveil.”

Patrick's announcement is expected to come after her Daytona 500 appearance, with Ed Carpenter Racing, Dreyer & Reinbold Racing and Schmidt Peterson Motorsports holding the final known seats for the Indy 500.