We have W2 employee on work visa, he filled out the tax witholdings form. But now he says medicare and SS be deducted retroactively. Is this our responsiblity as emplyr?

Hello, sales250. 

I'll point you to the right direction to help you know your tax responsibilities and handle the retroactive deductions. 

Regarding the tax responsibility, I would highly recommend reaching out to a tax advisor. They guide you in handling the tax-related implications of retroactive taxes and ensure you're compliant with the IRS.

You can also check with the IRS for instructions about retroactive tax deduction responsibilities. 

After getting the instructions and all the details regarding the retroactive deductions, you'll want to contact our support. They can adjust your employee's taxes if there's a need for the medicare and social security to be deducted retroactively. 

Here's how to reach them: 

1. Click the Help menu. 
2. In the chat box, type "talk to a human."
3. Click the Get help from a human option.
4. Choose how you want to contact us. 

After dealing with the taxes, do you need help running reports to see your employees' year-to-date data and other payroll information? Check out the guides here: Run payroll reports.

You're still welcome to post your replies here if you have questions managing your employees. Do you also have other tasks to complete in QuickBooks? Let me know and I'll be sure to help you out.