I am receiving social security disability 100%...I have purchased a small Flea Market/Auction House and have formed a LLC...

Yes, it definitely could. Although you are "100% disabled" that could change. Have you reported this to SSA as the information provided to you when you won your benefits instructed you to do?  When you do, although you may be given information by SSA about this LLC, you can't rely on it, that is: you really need to seek local counsel that has your interests in mind when advising you. Income is not the only thing that SSA looks at when reviewing your case, when they review it, which they are required to do on a regular basis.  In the event that they find you are no longer disabled, perhaps 3-5 years from now, you may be in an overpayment status, that is, the SSA will be asking you to re-pay benefits that they have paid you. Although you have set up an LLC, this does not protect you.  In fact, there are three different methods by which SSA can review your situation to determine that you are not disabled. See http://ssa.gov/pubs/10095.html and http://www.socialsecurity.gov/redbook/