Productivity Get prepared to report your work activity to the SSA on 821-BK Form When you want to claim Social Security disability benefits, you should be prepared for a thorough inspection by the Social Security Administration (SSA) as they are obligated to make ... Productivity Form SSA-3373-BK: How to report your disability conditions to the SSA Form SSA-3373-BK, Function Report – Adult Today’s review is devoted to one of the most important documents when applying for Social Security benefits – Form SSA-3373-BK, Function Report – ...