If my job as a work-study isn't taxed for medicare and social security, why am I being told I owe federal taxes?

[tbga869134]

I worked as a work-study, which do not pay social security or medicare tax, but I am being told I owe money for not paying those taxes.

[HelenC12]

Even though you don't pay SS and Medicare tax, you may still have to pay federal income tax (FIT) and state income tax (SIT), if your state has an income tax.

Most U.S. citizens and most people who work in the United States need to pay taxes on the income they earn above a set minimum amount. There are four possible taxes you may have to pay:

1. Federal income tax (FIT), 
2. state income tax (SIT), 
3. Social Security (SS), and 
4. Medicare. 

[Opus 17]

How do you enter the income? Did you enter it as self-employment?  What kind of paperwork did you get?