If your medical records indicate you were disabled in 8-'08, and you are claiming that date as your "alleged onset date", the judge may rule your case as "fully favorable". This would mean that you would be eligable for back pay from the date you alleged you were disabled and unable to work. (8-'08) If the judge feels that your records do not prove disability from your alleged onset date, he may issue a less favorable ruling, wherein he may feel you were disabled as of your filing date. In which you would receive back pay from 1-'09 forward! Strong ongoing medical records are of the essence! My case was assigned to the toughest judge in the Dallas area, but because my records were complete and ongoing, he approved me. I also followed up, and made sure that all pertinent medical records were in my file. This is your attorneys job, but you are the one that stands to lose the most if your file is incomplete, so be proactive!!! Good luck!!!!!