Higher rate of OASDI/EE and MED/EE

As I know, Federal Old Age, Survivors, and Disability Insurance/Employee Expense (OASDI/EE) and Medicare (MED/EE) are mandatory at rates of 6.2% and 1.45% of taxable income, respectively.

However, my pay stub reflects much higher percentages. My Fed OASDI/EE is 9.2%, and Fed MED/EE is 2.15% of my taxable income. I am on a work visa and classified as a resident for tax purposes.

Are there specific reasons for the higher rates? If this is an error, will my employer correct it, or how can I go about correcting it?