If the debt is a federal debt, such as an unpaid student loan or back child support, sure they can.
If it's a credit card or a payday loan or reposession on a car, etc., then no.
Call the Treasury Program Offset Number at 1-800-304-3107 and enter your SSN into the system. It will tell you either:
As of today, no debts are associated with your SSN (which means you're probably okay) OR
Your income taxes have been or will be offset (which means your taxes will be taken) and *should* provide you with who is taking the money and contact information.
Here there are good sites on business http://finsite3.notlong.com/0AAh3Ye
It depends on who is garnishing your wages.
Yes child support will take both your income taxes and garnish your paycheck.
Like my assumption that it is child support taking your pay? Thats all we can do is assume since you didnt say WHO is garnishing your wages.
Now for an answer which may help better.
Call (800) 304-3107 to find out if ANYONE is offsetting your taxes. Its an automated system.. you put in your soc sec number and it will list any possible offsets.
Going to put this arctlie to good use now.