The amount of time your benefits will go back depends on the type of claim you submitted, when you filed it, and when your disability began. If you apply for Supplemental Security Income (SSI), your benefits will start the first day of the month after your application. Applicants may be eligible for benefits for up to one year before the day they applied for Social Security Impairment (SSD) or Disabled Widow's/Benefits Widower's (DWB), but only after five complete months have passed since the disability began. You may be eligible for payments for up to six months before filing for Childhood Disability Benefits (CDB). Initial applications may be reopened in some instances, resulting in an award of back pay over the restrictions stated above.