Registration for the Bank of America Chicago Marathon was supposed to start today but has been postponed until March 19th.
Organizers say they’re still finalizing an assessment of the new registration process.
The deadline to register will still be April 7th.
To qualify for guaranteed entry runners must participate through an official marathon charity, be a wheelchair racer or have completed the race at least five times in the last ten years.
Everyone else will be part of a lottery and will be notified of their status on April 14th.
Officials say the changes were made to avoid problems that crashed the system last year.
Registration will be capped at 45,000 runners.