Congress is poised to enact a law denying or revoking passports for U.S. citizens who haven’t paid their taxes.

Under a new law expected to take effect in January, the State Department will block Americans with “seriously delinquent” tax debt from receiving new passports and will be allowed to rescind existing passports of people who fall into that category. The list of affected taxpayers will be compiled by the Internal Revenue Service using a threshold of $50,000 of unpaid federal taxes, including penalties and interest, which would be adjusted for inflation.

The rule has been passed in similar versions by both the House of Representatives and the Senate. It is part of a highway-funding bill, H.R. 22, that is before a conference committee. Congress is expected to pass it in early December.

In most cases, the passport provision would apply if a taxpayer is subject to a lien, which advises creditors of a debt to the IRS, or a levy, which gives the IRS the authority to seize assets. It wouldn’t apply if a taxpayer is in the process of resolving tax debt with the IRS, such as by paying it on an installment plan, or if the taxpayer is contesting the collection either administratively or in court, said David Kautter, a partner at the accounting firm RSM in Washington.

However, the State Department could issue a passport in an emergency or for “humanitarian reasons.” Neither the State Department or Treasury Department would comment while the legislation is pending.