You only need to be a full-time student for any 5 months out of the year. A month counts even if you only attended for one day during that month. Also, full-time is defined by the school, so whatever they consider as full-time is what matters. Sometimes, fewer credits are required to meet that definition during the summer sessions.
If you don't meet the student criteria, you could still be a dependent if you earned less than $4150 during the year.
