Q. In this case the class cost 8K but it was deemed Non-Taxable. So in that case I don't report it correct?
A. That's correct.
Q. But if the limit is $5250, how do they get to say it's not taxable?
A. If they determine, under IRS rules, that the education/training helps improve the employee's current job skills, they can declare it as a business expenses (as opposed to just being tuition reimbursement).
Reference: https://www.irs.gov/pub/irs-pdf/p5137.pdf
