Boston Marathon 2025 Registration Fee. What is the cut off time. Registration for the 129th boston marathon, presented by bank of america, the boston athletic association (b.a.a.) begins tomorrow, september 9 and will run for five days, closing on september 13.

This fee will be processed once a runner has been accepted as an official participant. The 129th boston marathon will take place on monday, april 21, 2025.