Can you be on methadone and have plastic surgery?

I don't see any reason why your methadone maintenance should prevent you from having surgery. In the hands of a good physician, surgeon and if needed, anesthesiologist, combined with good pain management and preparation, your goals are achievable Congratulations on both fronts. 

Many patients require urgent or necessary surgery while they are on methadone. The management of post-operative pain is obviously trickier, but it is possible to work through it successfully. When we are doing elective cosmetic surgeries we have the luxury of being able to plan ahead and hopefully make the surgical experience safer and more comfortable for you. Most people on methadone work with a pain specialist. Usually we (plastic surgeons) like to work with that specialist to come up with a plan given your specific issues. Once the plan is made typically the pain specialist orders and manages the medications that you will need. Getting you through a surgery safely and comfortably just takes planning and coordination between your doctors to help you achieve your goals!

Pain management is complicated by patients on methadone chronically but it certainly possible to have the operation done safely.