Tricare approves a set number of visits per referral. If you need more visits and aren't switching to a new physician/group, then the physician's office will usually contact Tricare to cover more visits . If you are switching doctors/groups even if it is for the same medical issue, then you get your PCP to make a new referral. Just remember that every referral must go through your Primary Physician even if a specialist is the one sending you to a different specialist (For example, my husband's urologist was sending him and the medical results to Mayo, but the actual referral still had to be requested by our PCP.).The trick is to be sure that each time you switch doctors/location, you get your PCP to make the referral first. Always follow-up to be sure it is authorized before your first visit. (They do this quickly and you can check the authorization online.) I have also found when I have called Tricare's insurance number with questions or problems they are ALWAYS nice and work to quickly resolve any issues. For example we were referred to a particular physician for radiation. Even though the entire group accepted Tricare Prime, this physician was new and had not yet made it onto Tricare's approved physician list. It was initially denied because he wasn't recognized, but after talking to them on the phone and explaining the situation. it was subsequently approved. I hope this helps. I do know that our insurance is much better than most. Also, thank you for your service!