Interested runners can help raise money for the Children's Miracle Network Hospitals.
A total of 7,000 runners will compete in the 26.2-mile race on Oct. 20.
The popular marathon has sold out for eight years.
Last year's event sold out, prompting race organizers to raise the bar to 5000 starters.
Runners can still participate through the Fundraise to Run Program.
Registration is now open for one of the largest Halloween-themed races in the U.S.
Runners wishing to raise money for charity can still find a bib.
The switching problem has been addressed thanks to a new lottery.