Effective this month, seriously delinquent taxpayers (defined as $51,000 or more to the IRS, where liens have been filed) may get their passports revoked or denied. This is the implementation of legislation that was passed in December 2016. Go to this link for additional information.
A chapter 7 or chapter 13 bankruptcy can be many cases discharge older taxes, and at the very least, suspend the IRS’ ability to collect involuntarily.