The U.S. federal government provides a limited amount of financial aid every year. The exact amount is set by legislation and the primary qualification is for a student to demonstrate actual financial need. Unfortunately, a lot of eligible students don’t actually get any help paying for tuition.
With school costs constantly rising at record speeds, there is never enough for everyone regardless of how much extra financial aid is voted into the system every year. Since not everyone who needs the money can have the amount promised, it all comes down to who asks first and follows all of the directions.