One of the qualifiers for disability eligibility is that your disability has to have lasted for at least one year or be expected to be last for that 12-month period. If you expect to be out of work for one year or more on account of illness or injury, you should file for Social Security disability benefits immediately. You don’t want to wait until the 12 months has gone by to start this process, which can sometimes take years to win. Example could be recovery from serious injury or surgery, or a requirement for lengthy chemotherapy.
How about if you are drawing workers’ comp? You do not have to wait until the worker’s compensation ends and you should not wait that long. You can file a claim for Social Security disability benefits while receiving worker’s compensation benefits. If you eventually win, there will be an offset calculated by Social Security, but the main takeaway is that you should file early. If your condition resolves, you can always withdraw your claim.