Could my refund be lower because I did not pay FICA taxes? (VISA opt to h1b)

[fz234]

I changed status from non-resident to resident last year (2018) because I went from an OPT VISA to H1B visa. I haven't paid the FICA (Medicare and social security) for the whole 2018 year because my employer treated me as non-resident for the whole year. I then tried to use Sprintax but it said I am a resident so I used TurboTax and got a refund already (with a w2 showing 0 on FICA taxes paid). 

Now my employer said I have to pay him back of the FICA taxes I did not pay from October to the end of the year. Should I request another w2 for 2018 showing I paid the FICA from October to the end of the year? 

Did Turbotax calculate that I owe the FICA taxes and lowered my refund? How do I know?  

[KarenJ]

When date did  you first arrive in the US as an international student and what visa did you have?

[fz234]

Hi, I arrived in 2016 with f1 opt after previous stays as a tourist. Sprintax told me I had file as resident so I used turbotax.

[KarenJ]

When did you receive your HIB visa in 2018?  Are you married?  Thank you!

[fz234]

I got it October 1 2018

[fz234]

I am single

[KarenJ]

I do not know why Sprintax told you that you were a resident.  If you were not in the US for 5 years or part years on an F1 visa, then you were a nonresident up until October 1, 2018. 

Then starting October 1, 2018 you can start counting your US days of presence for the substantial presence test.  You had less than 183 days of presence in the US in 2018.  So you were a nonresident in 2018 and need to amend your return to file a nonresident return with Sprintax.

You are a US resident starting January 1, 2019. Please see example 1 https://www.irs.gov/individuals/international-taxpayers/alien-residency-examples

Unless I am missing something. you should file an amended return.

[fz234]

I checked Sprintax another time. Apparently if I put my two 2 weeks vacations of 2013 and 2014 (tourist visa) it says I am considered resident, if I put the first entrance in US in august 2016 it says I am non-resident for tax purposes...

[fz234]

Below my visits
2013 - 2 weeks as tourist
dec 2014- gen 2015 - 2 weeks total a tourist
aug 2016 - dec 2016 f1
all 2017 f1
gen 2018 to sept 2018 f1
oct 2018 h1b

if I put these dates on sprintax it sayd I am resident, if I delete my tourist visits says I am non-resident, how is that possible?