The current mortgage interest deduction is $1 million. The House version of the tax bill called for a $500,000 cap while the Senate left it untouched. They split the difference and capped it at $750,000. Congress is expected to pass H.R. 1 this week
If we really want more people to use transit, and we think it's a worthwhile goal to subsidize people's commutes, why go through all the trouble of tax deductions and employer control? Why not just subsidize transit passes directly?