Summer School Enrollment Deadline is April 29
From the DCPS website:
DCPS will continue to offer enriching, rigorous and engaging summer school programs for students in kindergarten through grade 8 and high school students within three credits of graduating (this will be determined by the school counselors). Please be aware that due to a limited capacity and available spaces at each site, enrollment will be on a first-come, first-served basis with priority given to DCPS students.
More detail and all the forms you need are on the DCPS website — just follow the link above. If you have trouble with the link, paste this text into your browser: