F1 non-resident alien on CPT; payroll shows unnecessary tax deductions

[heli]

I am F1 student, non-resident alien, just started CPT.
The payroll period is weekly.
It shows FIT (about 13.3%), FICA (about 6.2%) and MC (about 1.45%) tax deduced.
I think F1 non-resident alien are exempted from FICA. Also want to make sure what are "FIT" and "M.C." and do I get exmeption from that too?
Total about 20.95% has been deducted as taxes.

Also do i need to talk to my employer now, or should fill up the forms later?

Also I read somewhere that for weekply payroll earning (after adding 39.42 and subtracting allowance deductions) between ~160 to ~1300, the deduction is flat ~7.7$

[Visa Taxes Expert]

If you are F1 student for upto 5 years (including CPT) you are exempt from FICA Taxes (Social Security and Medicare Taxes)

You still have to pay Federal and State Taxes.

Contact your employer to not withhold FICA taxes in CPT, if they refuse you can file Form 843, Form 8316 with us, to get a refund.

Hope it helps!