As you pay into Social Security, while you work, you earn work credits. Generally, you must have must have 40 work credits and have earned 20 of them in the last ten years, to still be eligible for Social Security disability. You can earn a maximum of 4 credits per year (for 2006 you get 1 credit per $970 earned, so at $3,880 you get 4 credits). Naturally, if you are out of work you are NOT earning work credits. Again this means you should apply as soon as you can because your date of disability must have occurred at a time when you still had credits.