Nancy is 63, she is getting SSDI due to her health. Doug will be 66. When he retires is Nancy able to collect SS under Doug's social security's?

Nancy & Doug,
Yes, Nancy can switch to her spouse's benefit any time after Doug files for his retirement benefit. However, it may be better for Nancy to continue taking her disability benefit until her full retirement age (FRA), when it converts to a regular retirement benefit. She could suspend her retirement benefit at her FRA, strat collecting an excess spouse's benefit, and let her retirement benefit grow 32%. It depends on the amount of her SSDI and her spouse's benefit. Our software, MaximizeMySocialSecurity, can determine your best filing strategy.
Best,
Mike