Medicare supplement, once thought to be going the way of the dinosaurs, is making a strong comeback. Sales of the product — also known as “Med supp” or “Medigap” — are experiencing growth as 34 percent of seniors who enrolled in traditional Medicare last year also purchased a Medigap policy, according to a recent survey by Mark Farrah Associates, a company that provides market data to the health care industry. Both seniors and agents are finding Medicare supplement to be an attractive alternative to Medicare Advantage (MA).