| << 2022 | 2024 >> |

| # | pic | Versenyző | Nemz. | Autó | Csapat | Chassis/motor |
| 2 | Josef Newgarden | USA |
| Team Penske | Dallara IR18 - Chevrolet | |
| 3 | Scott McLaughlin | Új-Zéland |
| Team Penske | Dallara IR18 - Chevrolet | |
| 5 | Pato O'Ward | Mexikó |
| Arrow McLaren | Dallara IR18 - Chevrolet | |
| 06 | Helio Castroneves | Brazil |
| Meyer Shank Racing | Dallara IR18 - Chevrolet | |
| 6 | Felix Rosenqvist | Svéd |
| Arrow McLaren | Dallara IR18 - Chevrolet | |
| 7 | Alexander Rossi | USA |
| Arrow McLaren | Dallara IR18 - Chevrolet | |
| 8 | Marcus Ericsson | Svéd |
| Chip Ganassi Racing | Dallara IR18 - Honda | |
| 9 | Scott Dixon | Új-Zéland |
| Chip Ganassi Racing | Dallara IR18 - Honda | |
| 10 | Alex Palou | Spanyol |
| Chip Ganassi Racing | Dallara IR18 - Honda | |
| 11 | Marcus Armstrong (R) | Új-Zéland |
| Chip Ganassi Racing | Dallara IR18 - Honda | |
| 11 | Takuma Sato | Japán |
| Chip Ganassi Racing | Dallara IR18 - Honda | |
| 12 | Will Power | Ausztrál |
| Team Penske | Dallara IR18 - Chevrolet | |
| 14 | Santino Ferrucci | USA |
| A.J. Foyt Enterprises | Dallara IR18 - Chevrolet | |
| 15 | Graham Rahal | USA |
| Rahal Letterman Lanigan Racing | Dallara IR18 - Honda | |
| 18 | David Malukas | USA |
| Dale Coyne Racing with HMD Motorsports | Dallara IR18 - Honda | |
| 20 | Conor Daly | USA |
| Ed Carpenter Racing | Dallara IR18 - Chevrolet | |
| 21 | Rinus VeeKay | Holland |
| Ed Carpenter Racing | Dallara IR18 - Chevrolet | |
| 26 | Colton Herta | USA |
| Andretti Autosport w/ Curb-Agajanian | Dallara IR18 - Honda | |
| 27 | Kyle Kirkwood | USA |
| Andretti Autosport | Dallara IR18 - Honda | |
| 28 | Romain Grosjean | Francia |
| Andretti Autosport | Dallara IR18 - Honda | |
| 29 | Devlin DeFrancesco | Kanada |
| Andretti Autosport | Dallara IR18 - Honda | |
| 30 | Jack Harvey | Angol |
| Rahal Letterman Lanigan Racing | Dallara IR18 - Honda | |
| 45 | Christian Lundgaard | Dán |
| Rahal Letterman Lanigan Racing | Dallara IR18 - Honda | |
| 51 | Sting Ray Robb (R) | USA |
| Dale Coyne Racing with Rick Ware Racing | Dallara IR18 - Chevrolet | |
| 55 | Benjamin Pedersen (R) | Dán |
| A.J. Foyt Enterprises | Dallara IR18 - Chevrolet | |
60 |
Simon Pagenaud | Francia |
| Meyer Shank Racing | Dallara IR18 - Honda | |
77 |
Callum Ilott | Angol |
| Juncos Hollinger Racing | Dallara IR18 - Chevrolet | |
78 |
Agustin Canapino (R) | Argentín |
| Juncos Hollinger Racing | Dallara IR18 - Chevrolet |
| # | pic | Versenyző | Nemz. | Autó | Csapat | Chassis/motor |
| 20 | Ryan Hunter-Reay | USA |
| Ed Carpenter Racing | Dallara IR18 - Chevrolet | |
| 23 | Ryan Hunter-Reay | USA |
| Deyer & Reinbold Racing | Dallara IR18 - Chevrolet | |
| 24 | Stefan Wilson (R) | Angol |
| Dreyer & Reinbold Racing / Cusick Motorsports | Dallara IR18 - Chevrolet | 24 | Graham Rahal | USA |
| Dreyer & Reinbold Racing / Cusick Motorsports | Dallara IR18 - Chevrolet |
| 30 | Conor Daly | USA |
| Rahal Letterman Lanigan Racing | Dallara IR18 - Honda | |
| 30 | Juri Vips (R) | Észt |
| Rahal Letterman Lanigan Racing | Dallara IR18 - Honda | |
| 33 | Ed Carpenter | USA |
| Ed Carpenter Racing | Dallara IR18 - Chevrolet | |
| 44 | Katherine Legge | Angol |
| Rahal Letterman Lanigan Racing | Dallara IR18 - Honda | |
50 |
RC Enerson (R) | USA |
| Abel Motorsports | Dallara IR18 - Chevrolet | |
60 |
Conor Daly | USA |
| Meyer Shank Racing | Dallara IR18 - Honda | |
60 |
Linus Lundqvist (R) | Svéd |
| Meyer Shank Racing | Dallara IR18 - Honda | |
60 |
Tom Blomqvist (R) | Angol |
| Meyer Shank Racing | Dallara IR18 - Honda | |
| 66 | Tony Kanaan | Brazil |
| Arrow McLaren | Dallara IR18 - Chevrolet | |
| 98 | Marco Andretti | USA |
| Andretti Herta Autosport w/ Marco Andretti and Curb-Agajanian | Dallara IR18 - Honda |