You're linking two separate governmental agencies together that don't care one bit about the other. Your SSD is based off of your disability, and then how much you've worked along with your age and some other stuff like that all added together.

Being audited is just a luck of the draw or if you had some items that we're flagged because of being a bit unusual. On a average 1 in 10 are audited and when there's extensive medical costs that number can be as high as 1 in 5 so don't worry. As long as you can prove your expenses most people often learn they're owed more than they originally thought instead of the other way around. It's only when there's some unique business expenses that the IRS gets a little nasty and I'm glad they do. It's time the average tax payer stop supplementing the two martini business lunch while we ate at McDonald's on our own dime.