| | Heat | Dash | B Feature | A Feature |
|---|
|
|---|
| 3/26/2021 | Humboldt Speedway - Humboldt, KS King Of America $5,000 to win + Battle Qualifying A Modifieds: USMTS - United States Modified Touring Series B Modifieds, USRA B-Mods, USRA Stock Cars | Results | | Austin Siebert (A Modifieds) | 3rd | - | 4th | - |
|
| 3/27/2021 | Humboldt Speedway - Humboldt, KS King Of America $20,000 to win, Battle at the Bullring $10,00 to win A Modifieds: USMTS - United States Modified Touring Series B Modifieds, USRA B-Mods, USRA Modifieds, USRA Stock Cars | Results | | Austin Siebert (A Modifieds) | 4th | - | 1st | 13th |
|
| 5/7/2021 | Lakeside Speedway - Kansas City, KS Weekly Racing #3 Factory Stocks, Stock Cars, A Modifieds, Midwest Modifieds, B Modifieds, Dirt Late Models | Results | | Austin Siebert (A Modifieds) | 2nd | - | - | 1st |
|
| 5/8/2021 | Central Missouri Speedway - Warrensburg, MO Race #4, Rick Beebe Heating and Air Conditioning Race Night. Weekly Racing #4. Lightning Sprints: POWRi Midwest Lightning Sprints Hobby Stocks, A Modifieds, B Modifieds, Super Stocks | Results | | Austin Siebert (A Modifieds) | 4th | - | - | 5th |
|
| 5/14/2021 | Lakeside Speedway - Kansas City, KS USMTS A Modifieds: USMTS - United States Modified Touring Series Midwest Modifieds, USRA B-Mods, USRA Stock Cars | Results | | Austin Siebert (A Modifieds) | 3rd | - | - | 8th |
|
| 5/15/2021 | Tri-State Speedway - Pocola, OK 7th Annual USMTS Driver4JRT.com Juggernaut - $10k to win! A Modifieds: USMTS - United States Modified Touring Series Pure Stock, USRA B-Mods, USRA Factory Stocks | Results | | Austin Siebert (A Modifieds) | 1st | - | - | 2nd |
|
| 6/4/2021 | Park Jefferson International Speedway - Jefferson, SD $10,000 to win USMTS Challenge plus Stocks, Sp Mods, Hobbies A Modifieds: USMTS - United States Modified Touring Series B Modifieds, IMCA Northern SportMod, IMCA Stock Car, IMCA Hobby Stock | Results | | Austin Siebert (A Modifieds) | 5th | - | 2nd | 13th |
|
| 6/5/2021 | Hamilton County Speedway - Webster City, IA USMTS $10,000-to-Win A Modifieds: USMTS - United States Modified Touring Series USRA B-Mods, USRA Modifieds, USRA Hobby Stocks, USRA Stock Cars, USRA Tuners | Results | | Austin Siebert (A Modifieds) | 6th | - | 7th | - |
|
| 6/17/2021 | Cedar Lake Speedway - New Richmond, WI 22nd Annual Masters A Modifieds, Dirt Late Models, USRA Modifieds, USRA Late Models | Results | | Austin Siebert (USRA Modifieds) | 8th | - | 11th | - |
|
| 6/18/2021 | Cedar Lake Speedway - New Richmond, WI 22nd Annual Masters A Modifieds: USMTS - United States Modified Touring Series Dirt Late Models, USRA Late Models, WISSOTA Modifieds | Results | | Austin Siebert (A Modifieds) | 6th | - | 6th | - |
|
| 6/19/2021 | Cedar Lake Speedway - New Richmond, WI 22nd Annual Masters Limited Sprints - Winged: Upper Midwest Sprint Car Series A Modifieds: USMTS - United States Modified Touring Series Dirt Late Models, USRA Late Models, WISSOTA Modifieds | Results | | Austin Siebert (A Modifieds) | 4th | - | 17th | - |
|
| 7/17/2021 | Lucas Oil Speedway - Wheatland, MO 15th Annual Diamond Nationals Dirt Super Late Models: Lucas Oil MLRA with Lucas Oil Late Model Dirt Series USRA Modifieds, USRA Stock Cars | Results | | Austin Siebert (USRA Modifieds) | 4th | - | - | 20th (DNF) |
|
| 8/6/2021 | Humboldt Speedway - Humboldt, KS USMTS $10,000 to win + Humboldt Speedway Weekly Racing Series A Modifieds: USMTS - United States Modified Touring Series Factory Stocks, Midwest Modifieds, USRA B-Mods, USRA Tuners | Results | | Austin Siebert (A Modifieds) | 8th | - | 9th | - |
|
| 8/7/2021 | Lucas Oil Speedway - Wheatland, MO 12th Annual USMTS Slick Mist Show-Me Shootout Presented by Foley Equipment A Modifieds: USMTS - United States Modified Touring Series USRA B-Mods, USRA Modifieds, USRA Stock Cars | Results | | Austin Siebert (A Modifieds) | 4th | - | 4th | 11th |
|
| 9/5/2021 | Central Missouri Speedway - Warrensburg, MO Race #23, SPECIAL EVENT, Labor Day Weekend, $3,000-to-Win B-Mods! Lightning Sprints: POWRi Midwest Lightning Sprints Hobby Stocks, A Modifieds, B Modifieds, Super Stocks | Results | | Austin Siebert (A Modifieds) | 4th | - | - | 3rd |
|
| 9/8/2021 | 81 Speedway - Park City, KS “T-Mobile Night at the Races” Keeper of the Plains USMTS Race A Modifieds: USMTS - United States Modified Touring Series USRA B-Mods, USRA Modifieds | Results | | Austin Siebert (A Modifieds) | 4th | - | 3rd | 16th |
|
| 9/10/2021 | Lakeside Speedway - Kansas City, KS Tom Karrick Memorial Factory Stocks, Stock Cars, A Modifieds, B Modifieds, Mod Lites | Results | | Austin Siebert (A Modifieds) | 5th | - | - | 8th |
|