Can the IRS seize and sell jointly owned property?

Unfortunately they can in certain circumstances.  There is a recent case that ended up going to the Seventh Circuit Court of Appeals.  In that situation a father and son owned the land jointly and the father owed the tax.  The son objected that he would be harmed as an innocent party but the Court found for the IRS and said that although the son was an innocent party he would not face undue hardship for three reasons: (1)  he did not live on the land, (2) he would be receive his half of the proceeds of the sale and (3) he could bid on the property at the auction if he so desired.  Thus each case is viewed in light of the particular facts of the case.  Depending on the facts, we might be able to stop the IRS in your case.