Get your taxes done using TurboTax

Per IRS Publication 8919, you use form 8919 to report social security and Medicare taxes due on compensation if you were an employee but were treated as an independent contractor:

Is doesn't seem like @Phstmv was being treated as an independent contractor, but his payroll taxes were not being withheld. If you look at form 8919, there are not options to indicate that your employer did not withhold the proper amount of payroll taxes.

I would suggest you ask your employer if they can correct your W-2 to reflect the proper payroll tax and allow you to pay in your share if necessary. Also, it may be that you were not required to pay payroll taxes so that is why your employer didn't do so.