I got notice a couple months ago about TGSLC initiating a wage garnishment for my student loans (~14K) They started soon thereafter and read on their website about how much they can take. It says that they can take up to 15% of the disposable income. That number is one that I can handle....

They started on my first pay period of November and so far they have taken ~1450. That seemed a little steep so I looked a little deeper. They are taking 15% of my gross income, not my "disposable" Is that the norm or is this a clerical error?

Your employer does all the calculations...talk to them.

http://www.ed.gov/offices/OSFAP/DCS/awg.employers.guide.html

Has the sheets that the employer does their calculations on.