The Boston Athletic Association and Quest Diagnostics announced that Quest will be the exclusive provider of onsite COVID-19 testing for the 125th Boston marathon, to be held on October 11. The B.A.A. will work with Quest Diagnostics for test administration and results tracking. Entrants in the 125th Boston Marathon will need to either provide proof of vaccination or produce a negative COVID-19 test no more than 72 hours in advance of the race in order to participate. Quest Diagnostics will be the sole testing provider for entrants, staff and volunteers. The B.A.A. will collaborate with Quest to hold an onsite testing event in the days leading up to the race to ensure a uniform, convenient and seamless process to help ensure the safety of all participants. Quest Diagnostics also provides COVID-19 testing through its consumer-initiated testing service QuestDirect as well as to organizations across diverse industries seeking to foster safer environments, based on diagnostic insights. The company operates full-service laboratories across the country, including a facility in Marlborough, Mass.