Just got an e-mail from my tax preparer. If you reimburse any medical expenses of your employees, there's a new tax you'll have to pay and it's due by the end of July. It's $1/covered employee (jumping 100% to $2/employee next year) and you'll need to file IRS Form 720. For more info, see Form 720 instructions [irs.gov] (page 9).
NOTE: This is not intended to be a political discussion (any political comments will be removed per the ToS), but rather a heads up for any U.S. companies that reimburse medical expenses.