Twelve months in the short answer, but do not delay filing an application early if you believe your condition will prevent you from working that long. You can file for Social Security disability benefits on the very same day that you become disabled. Don’t make the mistake of waiting months and even years after becoming disabled before filing a Social Security disability claim. If you have suffered a serious illness or injury and expect to be out of work for a year or more, you should not delay in filing a claim for disability benefits.