Education

I have a question along the same lines, however slightly different. I used my employee benefit for education assistance at $5250 in 2019. My employer will pay up to 10k total and anything over $5250 is subject to income tax. I'm paying last year's taxes this year on my paycheck each month (bi weekly). I'm wondering if they tax the entire amount used as assistance or only what I went over the $5250. It seems like it's the former. I'm being taxed around $2200 total. 

 

I used all $5250 and went over by $3,073.60. 

Question is- should they be taxing the total:  $8323.60? 

Makes it a bit outrageous and not want to go over $5250 if they are taxing the whole thing as income. I don't know at what rate, but it has to to be at least 25% or more. 

 

I appreciate any help you can offer.