can my wife collect her benefit, now age 64, and switch to my higher spousal benefit at age 66 without diminishing that spousal 50% benefit
Hi,
No. If your wife starts drawing her own benefits before full retirement age (FRA), she'll be stuck with the reduction for age that comes with it. And, she'd be deemed to have also filed for spousal benefits as soon as you file for your benefits, possibly resulting in a reduced spousal rate as well.
For example, Jane's full retirement age rate (PIA) is $800, but she starts drawing at age 64 and receives a reduced rate of $693. Jane's husband files for his benefits when Jane is 65, and his PIA is $2000. Jane's unreduced spousal rate would be $200 (i.e. $2000/2 - $800), but is reduced to $183 because she starts drawing it at age 65. Thus, Jane's combined benefit rate is $876, as opposed to the full $1000 that she could have received if she had waited until FRA to take both benefits.
You and your wife should strongly consider using the maximization software available on this website to compare your options and determine your best filing strategy.
Best, Jerry