I came to US as J-1 student in 2013 and left in 2014. I received zero income during the period. Therefore, I did not file any tax return.

[linalan0]

I came back in 2015 as F-1 student, and changed my status to H-1B in 2018.
I filed taxes for 2015 (form 8843), 2016 (form 1040nr-ez and 8843), 2017 (form 1040nr-ez and 8843). What form should I file for 2018? I am not sure if when i came the first time in 2013-2014 should be counted toward the 5years allotment as exempt since I never submitted a form 8843 for both years. Please help!

[LinaJ2018]

If you stay for more than 183 days in 2018 (including both the F and H-1Bi visa), you would be a resident for tax purposes.  When you carry a J visa, then later change to an F visa, the five years lifetime exemption covers the years while you were on the J visa.  Therefore you are a nonresident from 2013-2017.  You would file a Form 1040 in 2018.  

[linalan0]

Should I still file 8843 forms for years 2013 and 2014 now?
Also, if I need to file as resident for tax purposes for 2018, am I responsible for FICA taxes for the whole year or only after my status changed to H-1B?

[linalan0]

Should I still file 8843 forms for years 2013 and 2014 now?
Also, if I need to file as resident for tax purposes for 2018, am I responsible for FICA taxes for the whole year or only after my status changed to H-1B?

[LinaJ2018]

You should have.  But if IRS did not further ask for it, I would not concern.  When did you change to H-1B?

[linalan0]

I changed to H-1B mid november 2018, before I was F-1

[LinaJ2018]

I see.  So in 2018, on your 184th day, this is when you become a US resident for tax purposes even you are on the F- visa.  I would suggest go back to the employer and have them fix it for you.

[linalan0]

If the employer cannot fix the FICA taxes withholding for 2018 because they use a third party payroll company, can I use form 8919 to report uncollected FICA taxes, and declare it through Schedule 4? Do I need to file SS-8 as well? I have always been a full time hired employee, never an individual contractor. Always received W-2s, never received 1099s