Physician Reimbursements by Medicare: will elderly patients be able to find doctors?

Medicare and Medicaid reimbursements are often below operating costs for doctors who choose to see patients covered by these insurance plans. While the number of patients on Medicare is rising, the number of doctors willing to see these patients is not growing to meet that demand. Will Medicare patients be able to find doctors willing to see them? What good is government health insurance if it can't get you in to see the doctor?