I am in the Army National Guard currently. I have approximately 4.5 years left on my contract. Can I do Air Force ROTC?

The NG would have to release you to sign an Air Force contract. This requires a DD368 usually approved by a General officer. This would be the same form you would need if you received a line scholarship for Army ROTC. So it is up to your unit to release you. There is no requirement for them to do so.

My short answer is Yes, especially if your pitch is that you want to be an Air National Guard officer in the same state.

Back in 1987, I got an early release from active duty ry to attend ROTC as a non-scholarship student. Did 2 years in ROTC & NG, and then went back on active duty as a new Army 2LT. It is possible, but as the Colonel said, my releasing unit had the option to approve or disapprove my request. I know that was a long time ago and did not include switching services, hope it helps to know it is possible.