If someone got a CPM paid for, it was a slip-up on Tricare's part. Also, they have gotten more strict in recent years. I know someone who had it paid for with my LM, but there was no way in heck they'd pay for mine!!!
Also, with Standard, it is not guaranteed they'd pay for the whole thing. The CNM would have to agree to be in-network. I had a CNM for my first birth (a hospital one!!) and got stuck paying $1500 out of pocket. We signed paperwork in the beginning of care with her fee on it, not realizing it meant WE had to pay it all. Read carefully and ask before signing anything!!! Tricare and their lawyers were really nice about it, they read what we signed and tried to find a loophole for us but there wasn't one.
That said, the birth went well and even though I didn't love that midwife it was still worth it since it was easier to have a natural birth. For our DD, who was a homebirth, there simply weren't any CNM's who did homebirth in the area, and even though Florida law mandates LM's be covered, Tricare would not pay. They are not an "insurance company" but rather a "government benefit" and thus do not fall under that law. *sigh* We paid the $3200 out of pocket but it was worth each and every cent! If you do wind up having to go that route, Tricare does, however, cover all your labwork, ultrasounds, etc 100% just like if they were done with an OB.