In general in the US, masters degrees which are not on a PhD track are not funded. That is there are not really opportunities to work as an RA or TA. As master's programs tend to be more professionally oriented, the expectation is that the student will take out student loans. In contrast, in PhD programs, the student does work for their professor, and therefore are funded.

My understanding (and this may be more true of the sciences than other fields) is that PhD students are strongly preferred for TA and RA positions. Both TA and RA positions build useful experience for PhD students by giving the PhD student experience with teaching and academic research.

As to the more general question of funding for masters programs, I would guess that you will probably have the most luck looking for opportunities specific to your situation (e.g. field of study), however in general masters students are expected to pay their own way.

In general in the US, masters degrees which are not on a PhD track are not funded. That is there are not really opportunities to work as an RA or TA. As master's programs tend to be more professionally oriented, the expectation is that the student will take out student loans. In contrast, in PhD programs, the student does work for their professor, and therefore receives funding.

My understanding (and this may be more true of the sciences than other fields) is that PhD students are strongly preferred for TA and RA positions. Both TA and RA positions build useful experience for PhD students by giving the PhD student experience with teaching and academic research.

As to the more general question of funding for masters programs, I would guess that you will probably have the most luck looking for opportunities specific to your situation (e.g. field of study), however in general masters students are expected to pay their own way.