The IRS Publication 970, Chapter 11, allows employees who receive tuition benefits from their employer to exclude only $5,250 per year from their taxes, and must pay taxes on any tuition amount above that. This has been the rate since 1986 (the first year that the archived Pub 970 is listed on the IRS.gov website), when the national average tuition was $2,918 for public four-year institutions.
The national average now is $9,410 for public institutions - a 222.48% increase! However, the same $5,250 that applied in 1986 still applies 30 years later. This should be updated to reflect the 116% inflation rate between 1986 and 2015. This should also be adjusted annually to reflect inflation.
[All rates given in adjusted 2015 dollars. Tuition figures from CollegeBoard.org, 9/15/2016]