What is the path to becoming a maintenance test pilot as an officer MEDEVAC pilot?

My buddy is a CPT, UH-60M MTP, and a 67J. It’s possible to get it, but it will depend on your unit sending you or not.

My response would be "dated", since I retired over 20 years ago, and much of my time was spent in the Guard. I went into the Guard as a former AH-1 Gunship pilot and ASO - with UH-1 and OH-58 ratings, and MAST (medevac) experience at Ft Carson. Since I had a civilian A&P, and desired maintenance, it was easy to "fall into" an open maintenance slot - which I eventually went to the UH-1 MTP course at Ft Eustis. When I began the MTP Phase II (UH-1), I got "bumped" due to an influx of a couple foreign nationals creating a shortfall in UH-1 availability, I was offered the OH-58 track due to my past qual, and State approved the "deal" since they had OH-6's and all I had to do was transition into an OH-6 when I completed the OH-58s. Fast forward a few years, and my AGR unit was being de-activated after Desert Storm. The State lost all its OH-6s and picked up OH-58s. My MTP in OH-58s sudldenly became vauable. Also, there was a newly activated Blackhawk medevac unit being formed in the State that needed an AGR MTP. I had both maintenance and medevac experience, so, much to my delight, they moved me into the slot - which sent me to Rucker for UH-60 qual, and back to Eustis for UH-60 maint qual. State also picked up some EH-60s that needed an MTP, so they also sent me to Ft Huachuca for the "Quick-fix (EH-60) qual. After I retired, my military experience helped me tap into the civilian multi-engine EMS program. In a nutshell, anything can happen depending on the needs of the service, and with enough funding availability. I'd say now could be a good time.