The simple answer to the question is you do not have to wait a day to file for disability benefits. The definition of disability is the inability to engage in substantial gainful activity due to an impairment or combination of impairments that is expected to last one year or result of in death. Unfortunately, many people believe that they have to wait a year before they can apply for disability benefits and that is simply not true. You do not have to wait any period to file for disability benefits.
Fortunately, if you did wait to apply for disability benefits you may still be paid for those months that you waited before you applied. Social Security Disability benefits are paid retroactively for a maximum of one year prior to the date of application; however, you must be disabled for five months before Social Security Disability benefits are payable. So, for example, if you stopped working on January 1, 2010 and applied for benefits on January 1, 2011, you will be payed from June 2010 forward.