If my Japanese wife draws both us and Japanese social security . She has worked in the united states for 20 years and is one year older than me. Her us social security is about $120 more on her own work record than if i claimed her on my social security as a spouse. Can she choose her work history which is higher or can she choose a lower about as on my work history as a spouse? All this to avoid WEP tax . We have not filed for US social security yet . Please advise
First of all, WEP (Windfall Elimination Provision) isn't a tax. Instead, it's an alternate method of calculating benefits that can be used when a person is drawing both Social Security retirement or disability benefits and a pension based on their work and earnings which were exempt from Social Security taxes (https://www.ssa.gov/pubs/EN-05-10045.pdf).
The only way that your wife could file for spousal benefits without also filing for her own Social Security retirement benefits is if she was born before January 2 1954 and she files effective with full retirement age (FRA) or later. However, even if WEP applies when calculating her own retirement rate it wouldn't hurt her overall rate if she also qualifies for spousal benefits. She couldn't draw spousal benefits any earlier than when you start drawing your benefits, though.
For example, say Jane is receiving a pension based on her earnings that were exempt from Social Security taxes. Jane's primary insurance amount (PIA), which is also her Social Security retirement FRA rate, would normally be $800, but due to WEP her rate is reduced to $450. Jane's husband is drawing his benefits and his PIA is $2000. If Jane files at FRA her spousal rate would be calculated by subtracting her WEP PIA of $450 from 50% of her husband's PIA, which in Jane's case is $550 (i.e. $2000/2 - $450). That would then be added to her own WEP rate to give her a combined rate of $1000. If Jane's own rate wasn't reduced for WEP she'd still get a combined rate of $1000, but in that case her own rate would be $800 and her spousal rate would be $200 (i.e. $2000/2 - $800).
Our software (https://maximizemysocialsecurity.com/purchase) is fully programmed to handle cases involving both WEP and non-WEP calculations, so you and your wife should strongly consider using it to do your Social Security planning.