It can be but does not have to be. There are many kinds off accounts, private, corporate, savings, deposit etc. Each offers different services according to the needs of the customer.
If the judgment is for state or federal taxes then any refund is subject to seizure by the agency holding the judgment.
If it is a creditor judgment, a tax refund would only be subject to...
A single creditor can only execute a judgment in one manner, that being the case a judgment creditor cannot concurrently garnish income and levy the bank account of a judgment debtor.