Money questions

As an international student I was told my stipend would be taxed, which I am really shocked about (this isnt the case in the UK) , anyone know what % this will be?

Also 3 years TA'ing typical? I was expecting 2 years TA'ing 3 years RA

TAing depends on research... if you are theory you might TA longer because the prof dont have the money to pay you.

It will be "taxed" but you get the money back or they will automatically see that there is a tax treaty, so they won't tax you.

Tax return is at the end of each year. and also if you start in September, you will be exempted of tax paying for the duration of 4 months up to December. it means they will start tax from the next January.

It depends partially on what state you are in. It's quite possible that the tax will end up being 0% because as a grad student, you are poor.