<p>Very few masters programs really require an undergraduate degree in the same field. The only real issue is preparation, and since graduate degrees get progressively more specific, all they really care about is your preparation in that specialty. A certain amount of remedial work is acceptable to most programs, as even same-field undergrad programs may not adequately prepare you for grad work in certain specialities, but they usually draw the line at around a semester or so of classes - perhaps 3-4.</p>
<p>This means that same-field undergrads have more options for grad school and will require less prep work once they get there. There are still limits, of course - NO ONE comes out of undergrad prepared for EVERY speciality. </p>
<p>Related-field undergrads will be in a similar boat, but the options narrow. There will still be an area or two where you can go in with little or no remedial work, but there will be more situations where you just don’t qualify. Still, it happens - in EE I know numerous people with math or physics degrees.</p>
<p>Loosely-related undergrads may only qualify under certain circumstances - someone with an urban planning undergrad could get into a masters program in civil engineering, but only if they had the right undergrad coursework and found a very specific program, professor, and research project. Even then they would probably need a semester of catch-up work.</p>
<p>When you get out with your degree, realize also that your marketability is keyed to your TOTAL education. Just as your grad options narrow or widen, so do your job options later on. Having a masters alone does not make the world your oyster.</p>