<p>The child does not have to be a full time student at the end of the year. They have to be under 24 and have been a full time student for 5 months of the year.</p>
<p>
I believe a permanently disabled child comes under the qualifying child rule so has to meet the support (not providing more than half his/her own support) rather than the gross income test (the personal exemption amount of $39000 for 2013). </p>
<p>The gross income test is for a qualifying relative (who does not have to actually be a relative at all!!).</p>