A 'medical elective' also refers to a period of time, usually 6-8 weeks during which medical students who are towards the end of their training, can do a medical placement in a different country or healthcare setting. Most students choose to go hospitals abroad. Students are expected to pay for this themselves and to write a report on their experiences to submit back to their medical school. Hope this is the right context for your question!

What is the full sentence? If this is from an insurance document it could mean an elective medical procedure. (cosmetic surgery, corrective laser eye surgery, etc)