The number of doctors who opted out of Medicare last year, while a small proportion of the nation's health professionals, nearly tripled from three years earlier, according to the Centers for Medicare and Medicaid Services. Other doctors are limiting the number of Medicare patients they treat even if they don't formally opt out of the system. The reductions are due to frustration with the program's payment rates and increasing rules.

All told, according to an article in The Wall Street Journal, health experts say the number of doctors going "off-grid" isn't enough to undermine the Affordable Care Act, but they say some Americans may have difficulty finding doctors who will take their new benefits or face long waits for appointments with those who do.