The city started giving every student free lunch under the federal program in 2015 because it was easier than processing the applications for all the students, at the time the majority of students qualified based on their family income. They don’t collect family income information anymore, students in federal hill get the same access to free breakfast and lunch as students in Carrollton ridge.

https://www.baltimoresun.com/education/bs-md-ci-poverty-undercount-20180202-story.html

It’s not universally done because it doesn’t make sense to give federally funded free meals to students who aren’t needed. Baltimore mismanaged the federal funding.