It means the 2009 Formula 1 world champion will team up once more, this time at IMSA's season-closing Road Atlanta endurance event, with his Garage 56 NASCAR Le Mans project team-mate Mike Rockenfeller, against whom he raced in NASCAR Cup at Indianapolis last weekend.
The 43-year-old, Los Angeles-domiciled Briton said he was "very excited" to be joining the Minnesota-based customer Porsche team, which joined the IMSA SportsCar Championship from Laguna Seca in May after supply chain delays in receiving its hybrid-powered 963.
"Whilst I'm having a lot of fun cutting my teeth in the NASCAR Cup series this year, a prototype with high downforce is definitely more in my comfort zone," said Button. "That said, the Porsche 963, the IMSA WeatherTech Sportscar Championship, and Road Atlanta are all brand new to me so I can't wait to tackle all three with my team-mates for the weekend.
"I partnered with 'Rocky' at Le Mans this year and he will be invaluable as he's fantastic at car/team development. He is also incredibly quick which always helps!
"I'll also have the pleasure of working with rookie Tijmen van der Helm who seems to really be gaining speed and confidence through the season so we should have a lot of fun."
Button has run three races in NASCAR Cup, driving the #15 Ford Mustang for Rick Ware Racing with support from Stewart-Haas Racing. He has a best finish of 18th at COTA, but qualified eighth at the Chicago Street Course.
Despite its delayed start, JDC-Miller MotorSports has scored three top-five finishes in IMSA this year, with season-high fourth places at Watkins Glen and Canadian Tire Motorsport Park
"JDC-Miller MotorSports is honored to confirm that Jenson will be joining us for the final race of the season in our Porsche 963 at Road Atlanta," said team boss John Church. "The team had hoped to have him join Rocky and Tijmen at Watkins Glen but unfortunately that did not work out as the very busy Jenson had some TV commitments.
"His accomplishments speak for themselves. He and Rocky bonded through the extensive development of the Garage 56 Camaro.
We are confident he will quickly integrate with the team and get up to speed with the 963."
Volker Holzmeyer, president and CEO Porsche Motorsport North America, added: "Having Jenson join JDC-Miller MotorSports is a testimony to the program John Church, John Miller and the entire team has assembled. It also speaks to the high level of competition and interest in the IMSA GTP class.
"'Rocky' and Tijmen have proven how successful a privateer can be with the Porsche 963. The addition of Jenson should bring even greater success."