The school, which is currently a grade 1-12 boarding school, will scale back operations starting with the 2014-2015 school year.
At that time, Girard College will become a grade 1-8 day school with no residential program.
There will be no change for the 2013-2014 school year.
The school says the tight economic times forced them to make the change, adding the moves are aimed at allowing time for the school's trust to grow back to "full financial health."
Girard has operated since 1848 as a free boarding school for poor children from single-parent families.