The Bachelors in Medicine and Bachelors in Surgery is an MBBS degree, commonly used in India and I think UK. It is more than pre-med in the US. It is used for physicians who must first complete additional training (like a residency here). In those countries, an MD is an option, but not required to become a physician.
I don't see it very often. I believe many US residency programs will not accept MBBS candidates. But an MBBS can become a licensed physician in the US. We have a 1 year training program for advanced pelvic surgery (not an approved fellowship) and there was 1 physician over the years that was MBBS.
But to answer the original poster, as stated previously, a resident may not independently bill (with certain primary care exceptions in an approved program.) Typically, resident services are billed only if properly supervised/provided by the teaching physician, under the teaching physician with -GC. If you fall under the primary care exception, they are billed with -GE. The Medicare reference provided by Thomas tells you everything you need to know.