| Car No. | Driver | Team | Engine | Rounds |
|---|---|---|---|---|
| 2 | Josef Newgarden | Team Penske | Chevy | Full Season |
| 3 | Scott McLaughlin | Team Penske | Chevy | Full Season |
| 5 | Pato O'Ward | Arrow McLaren SP | Chevy | Full Season |
| 06 | Helio Castroneves | Meyer Shank Racing | Honda | Full Season |
| 6 | Felix Rosenqvist | Arrow McLaren SP | Chevy | Full Season |
| 7 | Alexander Rossi | Arrow McLaren SP | Chevy | Full Season |
| 8 | Marcus Ericsson | Chip Ganassi Racing | Honda | Full Season |
| 9 | Scott Dixon | Chip Ganassi Racing | Honda | Full Season |
| 10 | Alex Palou | Chip Ganassi Racing | Honda | Full Season |
| 11 | Marcus Armstrong | Chip Ganassi Racing | Honda | Road/Street |
| 11 | Takuma Sato | Chip Ganassi Racing | Honda | Ovals |
| 12/1? | Will Power | Team Penske | Chevy | Full Season |
| 14 | Santino Ferrucci | AJ Foyt Racing | Chevy | Full Season |
| 15 | Graham Rahal | Rahal Letterman Lanigan Racing | Honda | Full Season |
| 18 | David Malukas | Dale Coyne Racing/HMD Motorsports | Honda | Full Season |
| 20 | Conor Daly | Ed Carpenter Racing | Chevy | Full Season |
| 21 | Rinus VeeKay | Ed Carpenter Racing | Chevy | Full Season |
| 24 | Stefan Wilson | Dreyer & Reinbold Racing/Cusick Motorsports | Chevy | Indy 500 |
| 26 | Colton Herta | Andretti Autosport | Honda | Full Season |
| 27 | Kyle Kirkwood | Andretti Autosport | Honda | Full Season |
| 28 | Romain Grosjean | Andretti Autosport | Honda | Full Season |
| 29 | Devlin DeFrancesco | Andretti Steinbrenner Autosport | Honda | Full Season |
| 30 | Jack Harvey | Rahal Letterman Lanigan Racing | Honda | Full Season |
| 45 | Christian Lundgaard | Rahal Letterman Lanigan Racing | Honda | Full Season |
| 51 | Sting Ray Robb | Dale Coyne Racing/Rick Ware Racing | Honda | Full Season |
| 60 | Simon Pagenaud | Meyer Shank Racing | Honda | Full Season |
| 77 | Callum Ilott | Juncos Hollinger Racing | Chevy | Full Season |
| 78 | Agustin Canapino | Juncos Hollinger Racing | Chevy | Full Season |
| 88 | Benjamin Pedersen | AJ Foyt Racing | Chevy | Full Season |
| 98 | Marco Andretti | Andretti Autosport | Honda | Indy 500 |
| TBA | Tony Kanaan | Arrow McLaren SP | Honda | Indy 500 |
| Car No. | Driver | Team | Rounds |
|---|---|---|---|
| 6 | Christian Rasmussen | HMD Motorsports/Dale Coyne Racing | Full Season |
| 7 | Christian Bogle | HMD Motorsports/Dale Coyne Racing | Full Season |
| 10 | Rasmus Lindh | HMD Motorsports/Dale Coyne Racing | Full Season |
| 27 | Hunter McElrea | Andretti Autosport | Full Season |
| 28 | Jamie Chadwick | Andretti Autosport | Full Season |
| 29 | James Roe | Andretti Autosport | Full Season |
| 39 | Nolan Siegel | HMD Motorsports/Dale Coyne Racing | Full Season |
| 51 | Jacob Abel | Abel Motorsports | Full Season |
| 68 | Danial Frost | HMD Motorsports/Dale Coyne Racing | Full Season |
| 75 | Matteo Nannini | Juncos Hollinger Racing | Full Season |
| 76 | Reece Gold | Juncos Hollinger Racing | Full Season |
| 99 | Ernie Francis Jr. | HMD Motorsports/Force Indy | Full Season |
| TBA | Louis Foster | Andretti Autosport | Full Season |
| TBA | Josh Green | HMD Motorsports/Dale Coyne Racing | Full Season |
| TBA | Jagger Jones | Cape Motorsports | Full Season |
| TBA | Josh Pierson | HMD Motorsports/Dale Coyne Racing | Full Season |
| TBA | Kyffin Simpson | HMD Motorsports/Dale Coyne Racing | Full Season |
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