Just now seeing this.
Take the course and take the NREMT once you finish the course. Once you pass the NREMT you can work anywhere in the states. The only thing you may have to learn is the local and state scope of practice as this can vary state to state, and county to county. But all in all, passing the NREMT is the most important thing you need to do. Otherwise you'll have to take the course over again when you move.
Wrong. NREMT is
NOT a license to practice anywhere.
Even for states that recognize NREMT and use that in place of doing their own testing, you still have to go to those states own EMS Agencies, fill out their applications (and pay their registration fees) and get approval from each individual state and the state will issue you a license or certification to practice in that state.
Live near the state lines and want to work in 2 or 3 states? You'll have to rinse, wash, and repeat in each individual state you want to practice in.
Some states will have additional requirements above and beyond simply having NREMT, you might have to pay for a fingerprint background check (California loves LiveScan...), you may need to sit through an actual formal class on local protocols, etc etc.
And that's just the state's that do recognize NREMT. There's still more than a few out there that do not. My current state (HI) for example, their education requirements to become an EMT are much greater than NR's, I cannot get state certified with only National, and there's currently no "bridge" program, is have to start over from scratch and attend their full EMT program (there's only 1 college program here that does it, and I think it's a 2 semester program including the prereqs you have to take before being allowed to take the actual EMT class).
So you have to look into tour state and local requirements, meet those, apply for local cerification/licensure befire you can work. More and more places are using NREMT as their requirement...but you still gotta do the local admin stuff first before you can work there.