An IRS levy permits the legal seizure of your property to satisfy a tax debt. It can garnish wages, take money in your bank or other financial account, seize and sell your vehicle(s), real estate and other personal property.
Retirement accounts, including IRAs, are not exempt from an IRS levy. Though state laws protect them from creditors, these laws do not apply to IRS agents. As long as the taxpayer can access his IRA and remove funds from it, the IRS is allowed to levy it.
https://www.irs.gov/businesses/small-businesses-self-employed/levy
