Is 500cc moderate plus profile a fairly large implant? I'm 5'5", 139 lbs, originally a B cup, would that put me in the D range?

Yes, 500cc is a big implant. It should get you into the D range unless you have a very wide chest and very small breasts. it sounds like your surgeon is being aggressive but responsible with the selection of size.

Thank you for your question.  Yes a 500 cc breast implant is considered a large breast implant.  Generally speaking 200 cc of breast implant can increase you 1 cup size in the bra you are currently wearing.  Based on that figure the 500 cc implants should increase you to a D cup in the bra you're currently wearing.Your chest and breast size limited the size of implant your surgeon could place.  For more information

There are a number of parameters surgeons use to help patients choose implant size, and occasionally a woman must choose a smaller implants than she might want to maintain an acceptable appearance. A commonly used limitation is to choose an implant that is not wider that the width of the breast. Depending upon the brand of implant, a mod+ for a 500cc saline would be 14.1 cm wide. A high profile implant limited to that width would allow a size of up to 650cc.  Width is not the only limitation, but since it is attached to a number it is easiest to discuss on a website. The elasticity of the skin is another factor that can be limiting. The best answer to your question would come from your surgeon, who advised you in the first place. All the best.