This works the same way as a Survivor Benefit, but it pays out even if you are still alive. If a qualifying event such as cancer, heart attack or stroke stops you in your tracks because you need to attend to your illness then you can accelerate your Survivor Benefit to pay extra bills, fill in because of lost income, or to use for special treatments, or additional help around the house.
The money paid in the acceleration will reduce the amount remaining in your Survivor Benefit but it might be the very reason why you can get by financially while you heal and get back on your feet.