I am married to a Japanese citizen who will be eligible for various government pension benefits from Japan. She is 57 years old as I write this. She has never worked in the USA and has not contributed anything to the social security system. I am a 63 year old US citizen and have contributed since my teens. I plan to wait until 70 before I apply for benefits. The USA and Japan have a Totalization Agreement that addresses social security benefits and payments for individuals and employers that are subject to payments to/from both countries.
Our current plan is to have me claim benefits when I turn 70 and at the same time apply for spousal benefits for my wife. I know that under US social security my wife will be deemed to have applied for the greater of her benefit or the spousal benefit.
In light of the Totalization Agreement:
a. Will this limitation also apply to her Japanese pension benefits or
b. Will she be able to collect both the spousal benefit based on my claim and her Japanese pension benefits?
Your wife won't be deemed to file for her Japanese pension benefits when she files for spousal benefits on your record, or vice versa.
Your wife can draw both spousal benefits from the U.S. and her Japanese pension. Foreign pensions are not considered as government pensions for purposes of the Government Pension Offset (GPO) provision (https://www.ssa.gov/pubs/EN-05-10007.pdf).