Tufts...ick. I have only dealt with them once, but they were a nightmare. I finally had to get the patient involved in a three way call to them, and only then did they pay the claim. Was a pre-cert call done first to verify that the L5000 was a covered code under the patient's benefits, etc? In my case I was dealing with L3000, and I had done the verification call first, and could use that as evidence of why the claim should be paid.
All I can tell you is that I have billed L5000 for a podiatrist to CGS DMERC a few times, and it always paid, no problems.