Registration for the Bank of America Chicago Marathon began at noon Wednesday for guaranteed and lottery entries for the Oct. 12 race.
This year all runners will be part of a lottery system unless they qualify for guaranteed entry. To qualify, runners must participate through an official Chicago Marathon charity, as an official international tour partner or as a "legacy finisher" who has finished the marathon five or more times in the past 10 years.
Men who have run a verifiable sub 3:15:00 marathon and women who have run a verifiable sub 3:45:00 marathon on or after January 1, 2012 also are guaranteed a spot in the race.
Everyone else who registers will be part of a lottery system. The race is capped at 45,000 runners.
Last year's registration was suspended after overwhelming demand crashed the site, and the remaining 15,000 bibs were doled out via lottery.
Guaranteed entry and lottery entry ends at noon on April 7. Lottery entrants will be notified of their status on April 14. Runners who were selected have three days to complete registration.
Registration initially was scheduled to span March 5 through April 7, but race organizers postponed it to finalize the assessment of the race's new registration process.