Security research firm Ponemon Institute estimates that 1.84 million adult-aged Americans have experienced medical identity theft, with 313,000 becoming victims during the past year. That's a 19 percent increase compared with a 2012 Ponemon estimate of 1.52 million who have in recent years been victimized by medical identity theft, based on an annual survey conducted each March and April. This year, the firm surveyed 788 adults who self-reported themselves or their families experiencing medical identity theft. Ponemon concludes that many cases of theft are easily preventable and victims can incur significant out-of-pocket costs. Here is a look at results of the survey, which the Medical Identity Fraud Alliance and ID Experts sponsored.