@BlueberryMuffinTop wrote:
I know that as an F-1 student we're exempt from paying FICA taxes,
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
An F-1 visa does NOT exempt you from FICA. Being a Nonresident Alien is what exempts you from FICA.
For the first 5 calendar years of a F-1 visa you are a Nonresident Alien. After that, you become a Resident Alien and are subject to FICA. So you became a Resident Alien (and subject to FICA) in 2016, and should have been paying FICA on any job income since then.
