I just recently changed my status from F-1 to H-1B, and now I owe all the FICA taxes that I was supposed to pay for when I was still employed on an F-1 visa with OPT.
I know that as an F-1 student we're exempt from paying FICA taxes, and my most recent F-1 visa in my passport was from 06/2017. However, once I switched my status from F-1 to H-1B and let my employer know about the change, they told me that I'm now liable to pay for the FICA taxes for when I was still employed as an F-1.
Is this correct, or is there some kind of misunderstanding? Do I have to back-pay my FICA taxes for when I was still employed as an F-1?
Timeline (I pass presence test for all the years):
08/2011 - 12/2015: F-1 visa, undergrad student
01/2016 - 09/2016: F-1 visa, further education student
09/2016 - 03/2018: F-1 visa, grad student
03/2018 - 10/2020: F-1 visa + OPT, employed
10/2020 - Present: H-1B visa, still employed
