| Time | Date | Name | Meet |
|---|---|---|---|
| 48.04 | Dec. 8, 2022 | Humberto Najera | Speedo Winter Junior Championship West |
| 49.26 | Nov. 5, 2022 | Ramon Jiang | CA RMDA Kevin B Perry Senior Meet |
| 49.75 | March 4, 2022 | Ramon Jiang | Speedo Sectionals - Carlsbad |
| 50.06 | Dec. 18, 2021 | Ramon Jiang | Speedo Sectionals - Huntington Beach |
| 50.08 | Dec. 17, 2021 | Ramon Jiang | Speedo Sectionals - Huntington Beach |
| 50.11 | Dec. 9, 2021 | Ramon Jiang | Speedo Winter Junior Championship West |
| 50.23 | March 2, 2018 | Jack Trujillo | Speedo Champions Series - Carlsbad |
| 50.62 | Dec. 16, 2017 | Jack Trujillo | Speedo Champions Series - CA NV |
| 50.63 | Dec. 9, 2017 | Jack Trujillo | Speedo Winter Junior Championships - West |
| 50.78 | Nov. 4, 2017 | Jack Trujillo | CA RMDA Kevin Perry Senior Invitational |
| 53.05 | Dec. 17, 2016 | Kyle Monteleone | CA December CA NV Sectional Championship |
| 53.31 | Nov. 5, 2016 | Kaikea Wilinski | CA RMDA Kevin Perry Senior Invitational |
| 54.24 | Dec. 18, 2015 | Kaikea Wilinski | CA RMDA Senior Invitational |
| 54.91 | Dec. 16, 2012 | Vladimir Quizhpe | Speedo Champions Series - Belmont, CA |
