| << 2020 | 2022 >> |

| # | pic | Versenyző | Nemz. | Autó | Csapat | Chassis/motor |
| 2 | Josef Newgarden | USA |
| Team Penske | Dallara IR18 - Chevrolet | |
| 3 | Scott McLaughlin (R) | Új-Zéland |
| Team Penske | Dallara IR18 - Chevrolet | |
| 4 | Dalton Kellett | Kanada |
| A.J. Foyt Enterprises | Dallara IR18 - Chevrolet | |
| 5 | Pato O'Ward | Mexikó |
| Arrow McLaren SP | Dallara IR18 - Chevrolet | |
| 7 | Felix Rosenqvist | Svéd |
| Arrow McLaren SP | Dallara IR18 - Chevrolet | |
| 7 | Oliver Askew | USA |
| Arrow McLaren SP | Dallara IR18 - Chevrolet | |
| 7 | Kevin Magnussen (R) | Dán |
| Arrow McLaren SP | 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 | |
| 12 | Will Power | Ausztrál |
| Team Penske | Dallara IR18 - Chevrolet | |
| 14 | Sebatien Bourdais | Francia |
| A.J. Foyt Enterprises | Dallara IR18 - Chevrolet | |
| 15 | Graham Rahal | USA |
| Rahal Letterman Lanigan Racing | Dallara IR18 - Honda | |
| 18 | Ed Jones | Dubai |
| Dale Coyne Racing with Vasser-Sullivan | Dallara IR18 - Honda | |
| 20 | Conor Daly | USA |
| Ed Carpenter Racing | Dallara IR18 - Chevrolet | |
| 20 | Ed Carpenter | USA |
| Ed Carpenter Racing | Dallara IR18 - Chevrolet | |
| 21 | Rinus VeeKay | Holland |
| Ed Carpenter Racing | Dallara IR18 - Chevrolet | |
| 21 | Oliver Askew | USA |
| Ed Carpenter Racing | Dallara IR18 - Chevrolet | |
| 22 | Simon Pagenaud | Francia |
| Team Penske | Dallara IR18 - Chevrolet | |
| 26 | Colton Herta | USA |
| Andretti Autosport w/ Curb-Agajanian | Dallara IR18 - Honda | |
| 27 | Alexander Rossi | USA |
| Andretti Autosport | Dallara IR18 - Honda | |
| 28 | Ryan Hunter-Reay | USA |
| Andretti Autosport | Dallara IR18 - Honda | |
| 29 | James Hinchcliffe | Kanada |
| Andretti Steinbrenner Autosport | Dallara IR18 - Honda | |
| 30 | Takuma Sato | Japán |
| Rahal Letterman Lanigan Racing | Dallara IR18 - Honda | |
| 45 | Santino Ferrucci | USA |
| Rahal Letterman Lanigan Racing | Dallara IR18 - Honda | |
| 45 | Christian Lundgaard (R) | Dán |
| Rahal Letterman Lanigan Racing | Dallara IR18 - Honda | |
| 45 | Oliver Askew | USA |
| Rahal Letterman Lanigan Racing | Dallara IR18 - Honda | |
| 48 | Jimmie Johnson (R) | USA |
| Chip Ganassi Racing | Dallara IR18 - Honda | |
| 48 | Tony Kanaan | Brazil |
| Chip Ganassi Racing | Dallara IR18 - Honda | |
| 51 | Romain Grosjean (R) | Francia |
| Dale Coyne Racing with Rick Ware Racing | Dallara IR18 - Chevrolet | |
| 51 | Pietro Fittipaldi (R) | Brazil |
| Dale Coyne Racing with Rick Ware Racing | Dallara IR18 - Chevrolet | |
| 59 | Max Chilton | Angol |
| Carlin | Dallara IR18 - Chevrolet | |
| 59 | Conor Daly | USA |
| Carlin | Dallara IR18 - Chevrolet | |
| 60 | Jack Harvey | Angol |
| Meyer Shank Racing | Dallara IR18 - Honda |
| # | pic | Versenyző | Nemz. | Autó | Csapat | Chassis/motor |
| 1 | J. R. Hildebrand | USA |
| A.J. Foyt Enterprises | Dallara IR18 - Chevrolet | |
| 11 | Charlie Kimball | USA |
| A.J. Foyt Enterprises | Dallara IR18 - Chevrolet | |
| 06 | Helio Castroneves | Brazil |
| Meyer Shank Racing | Dallara IR18 - Chevrolet | |
| 16 | Simona De Silvestro | Svájc |
| Paretta Autosport | Dallara IR18 - Chevrolet | |
| 24 | Sage Karam | USA |
| Dreyer & Reinbold Racing | Dallara IR18 - Chevrolet | |
| 25 | Stefan Wilson (R) | Angol |
| Andretti Autosport | Dallara IR18 - Honda | |
| 47 | Conor Daly | USA |
| Ed Carpenter Racing | Dallara IR18 - Chevrolet | |
| 52 | Cody Ware (R) | Brazil |
| Dale Coyne Racing with Rick Ware Racing | Dallara IR18 - Chevrolet | |
| 75 | RC Enerson | USA |
| Top Gun Racing | Dallara IR18 - Chevrolet | |
| 86 | Juan-Pablo Montoya | Kolumbia |
| Arrow McLaren SP | Dallara IR18 - Chevrolet | |
| 98 | Marco Andretti | USA |
| Andretti Herta-Haupert w/ Marco & Curb-Agajanian | Dallara IR18 - Honda |