Hey all,
I Completed my Master's and currently Im working in USA on OPT. How much tax is deducted(%) frm our monthly income, while on OPT? Also what forms besides the W4, are to be filled by students on OPT?

While you are on OPT, the same rules should apply that were in effect while you were a F-1 student, i.e. you pay federal, state and local income taxes, but you should be exempt from Social Security and Medicare taxes, but that is NOT a sure thing. The rules often vary from person to person.

Discuss the Social Security and Medicare tax exemption with your employer in detail. It is likely they are fully familiar with the rules as it applies to you