You have stated that Social Security Disability is not taxable as income. Is that from IRS Code section 104 (a)(1) or somewhere else?

If you do not have any other income than SS benefits, then it is not taxable.
A part of your social security benefits may be taxable if half of the SS benefits plus your other income exceeds the base amount. The base amount is $25,000 for single, head of household, married filing separately who did not live with the spouse in the year, and it is $32,000 for married filing jointly. For married filing separately who lived with the spouse any time in the year, the base amount is $0. Social Security Income and Disability Benefits Your U.S. Tax Return: The U.S. Income Tax Topics 1 (http://taxipay.blogspot.com/2008/08/us-income-tax-topics-1.html)