I'm TriCare Prime North (retired). My PCP submitted my referral to a surgeon on 7/1 - and I had the approval 7/7 (but I'm being told that was just the approval to meet with the surgeon).
In speaking with Tricare they only have a couple requirements - 100+ overweight and 1 or more comorbidity or 200 percent or more over ideal weight for height and bone structure. They do not require the supervised diet but the surgeon may. TriCare also told me that if the surgeon needs me to see a nutritionist that's my own cost as they don't cover nutritionists.
I have completed the seminar and my insurance has been verified - I have my 1st consult on 7/20 to discuss the next step (labs, psych eval, etc).
Good luck to you!