According to a recent survey of 1,433 emergency physicians:

• 73% reported seeing increased numbers of Medicaid patients who delayed medical care, because their health plans don't
  have enough primary care physicians in their "narrow networks" that limit the number of medical providers
• 67% reported that primary care physicians are sending patients to emergency departments for medical tests or procedures
  when health plans refuse to cover them in an office setting
• 60% reported trouble finding specialists for their patients, because of narrow network plans
• Over 80% reported treating patients who said they had trouble finding specialists, because of narrow network plans

Source: "Insurance Industry Drives Patients to Sacrifice Necessary Medical Care," American College of Emergency Physicians, October 26, 2015, http://newsroom.acep.org/2015-10-26-Insurance-Industry-Drives-Patients-to-Sacrifice-Necessary-Medical-Care