soccertese,

SS determines disability based upon a person's ability to work at or above (or even near in reality) the SGA level. What is this? Significant Gainful Activity is a dollar amount set by SS. In 2013 it was $1040. If your hourly rate is high enough, you don't have to work many hours to be disqualified.

Research the "grid rules" though. There are concessions made for workers ages 50 and 55, so if you can prove you were eligible this may help.

I'm not trying to discourage you, btw. You just DON"T want to focus on proving something that is irrelevant to SS.

The $1040 is a MONTHLY amount for SGA.

It takes about $1000 per year to earn one credit.

Just looked it up and the amount to earn ONE credit for 2014 is $1200. For the full 4 credits, your earnings would need to be $4800.