Restriction on working hours for full-time students I know that 20 hours/week when school is in session and 40 hours when school is out is the legal maximum working hour for international full-time students in United States. I was wondering whether this also holds for students other than international students. The website of U.S. Department of Labor mentions the same, but it is not clear whether it holds for all. Here is the extract from the website.

&quot;Full-Time Student Program
This program is for full-time students employed in retail or service stores, agriculture, or colleges and universities. The employer that hires students can obtain a certificate from the Department of Labor which allows the student to be paid not less than 85% of the minimum wage. The certificate also limits the hours that the student may work to 8 hours in a day and no more than 20 hours a week when school is in session and 40 hours when school is out, and requires the employer to follow all child labor laws. Once students graduate or leave school for good, they must be paid at least the federal minimum wage.
There are some limitations on the use of the full-time student program...&quot;
The extract you have linked is specifically for a program that exempts employers from paying the full minimum wage. There is, in principle, no law stating that students can only work 20 hours per week when school is in session. In fact, it's quite the opposite—students can work as many hours as they would like. 

On the other hand, it is possible for universities to place conditions on financial aid recipients that they not work more than some number of hours per week, and in general it's not really that smart of an idea to be studying full-time and working full-time on top of that. And the university may also have limits on what students can do with on-campus student aide positions, whether or not they are on financial aid.

But as far as the US government is concerned? I don't think they really care.