| ITF M15 Austin | 11/21 18:25 | 26 | Collin Altamirano v Preston Brown | 6-2,6-0 | |
| ITF M15 Austin | 11/20 18:50 | 25 | Collin Altamirano v Michael Shabaz | 7-5,6-2 | |
| Challenger Houston | 11/13 17:50 | 25 | [390] Collin Altamirano v Adrian Menendez-Maceiras [236] | 4-6,0-6 | |
| Challenger Houston | 11/11 21:10 | 24 | Gage Brymer v Collin Altamirano | 2-6,6-7 | |
| ITF M25 Malibu | 11/09 22:40 | 28 | [395] Collin Altamirano v Daniel Altmaier [364] | 6-7,6-2,5-7 | |
| ITF M25 Malibu | 11/08 18:00 | 27 | [429] Evan Song v Collin Altamirano [395] | 3-6,4-6 | |
| ITF M25 Malibu | 11/07 19:35 | 26 | [399] Austin Rapp v Collin Altamirano [395] | 1-6,3-6 | |
| ITF M25 Malibu | 11/06 00:40 | 25 | Isaiah Strode v Collin Altamirano | 2-6,5-7 | |
| Challenger Las Vegas | 10/15 17:30 | 24 | [373] Collin Altamirano v Kevin King [330] | 3-6,5-7 | |
| Challenger Fairfield | 10/07 18:00 | 24 | Brandon Holt v Collin Altamirano | 6-2,6-2 | |
| Challenger Tiburon | 09/23 20:30 | 24 | [292] JC Aragone v Collin Altamirano [358] | 6-2,7-6 | |
| Challenger Kaohsiung | 09/16 09:00 | 24 | [319] Teymuraz Gabashvili v Collin Altamirano [396] | 6-3,5-7,6-4 | |
| Challenger Shanghai | 09/13 04:35 | 27 | [438] Di Wu v Collin Altamirano [396] | 6-4,6-0 | |
| Challenger Shanghai | 09/12 04:20 | 26 | [396] Collin Altamirano v Tatsuma Ito [139] | 6-3,7-6 | |
| Challenger Shanghai | 09/10 04:00 | 25 | [256] Aleksandar Vukic v Collin Altamirano [396] | 4-6,6-7 | |
| Challenger Shanghai | 09/09 05:45 | 24 | [316] Collin Altamirano v Xin Gao [372] | 6-1,6-1 | |
| Challenger Jinan | 09/02 04:30 | 24 | [476] Di Wu v Collin Altamirano [316] | 6-4,6-4 | |
| Challenger Lexington | 07/31 19:20 | 25 | [274] Collin Altamirano v Roy Smith [314] | 4-6,7-6,2-6 | |
| Challenger Binghamton | 07/25 15:55 | 26 | [169] Dudi Sela v Collin Altamirano [283] | 6-4,7-5 | |
| Challenger Binghamton | 07/24 14:00 | 25 | [283] Collin Altamirano v Jeffrey John Wolf [261] | 6-2,7-5 | |
| Challenger Binghamton | 07/23 16:25 | 24 | [338] Lloyd Glasspool v Collin Altamirano [283] | 1-6,6-7 | |
| Challenger Gatineau | 07/15 17:35 | 24 | [284] Collin Altamirano v Brandon Holt [497] | 1-6,6-7 | |
| Challenger Winnetka | 07/11 17:25 | 26 | [115] Denis Istomin v Collin Altamirano [268] | 6-3,6-0 | |
| Challenger Winnetka | 07/09 16:45 | 25 | [268] Collin Altamirano v Thai-Son Kwiatkowski [205] | 6-3,6-0 | |
| Challenger Winnetka | 07/08 16:25 | 24 | [268] Collin Altamirano v Martin Redlicki [388] | 6-2,4-6,6-4 | |
| Challenger Columbus | 06/13 14:00 | 26 | [271] Collin Altamirano v Emilio Gomez [188] | 5-7,7-5,0-6 | |
| Challenger Columbus | 06/11 17:55 | 25 | Collin Altamirano v James Trotter | 6-3,6-1 | |
| Challenger Little Rock | 06/08 00:10 | 26 | Collin Altamirano v Raymond Sarmiento | 4-6,4-6 | |
| Challenger Little Rock | 06/04 15:00 | 25 | [277] Collin Altamirano v Alexander Sarkissian [345] | 6-3,6-1 | |
| Challenger Jerusalem | 05/22 07:00 | 25 | [478] Edan Leshem v Collin Altamirano [278] | 1-6,6-1,6-4 |