MTA runs a program for NYC school students, student who lives further than certain distance from school receives metrocard to ride subway and/or bus. There are many different students metrocards current and in the past. Some allowed students to rides both subway and bus 3 times a day free, some reduced fare to 50%, some allowed to ride only buses free or 50% reduced fare, some metrocards are valid during the weekdays some on weekends too.
Here are some images of those metrocards.
Some special student metrocards:
All green student metrocards for 7-12 grades have the same front looking side:
Here is only known to me green metrocards for all grades K – 12:
Green grade 7 – 12:
All orange student metrocards for K – 6 grades have the same front looking side:
Orange K – 6 grade metrocards: