For example, emergency rooms are required to treat anyone who comes through their door, regardless of ability to pay. When a person who is uninsured is treated and cannot pay for the services, the costs are passed on to other patients at the hospital.
As mentioned above, some doctors have complained that Medicare and especially Medicaid do not cover the costs of treating all of those patients, in which case the costs are passed on to private insurers who then charge higher premiums.
Of course, the challenge in universal health insurance is getting people who don't buy insurance now coverage they can pay for under a new plan.
The AMA has stated that it is not opposed to a public plan per se but is opposed to a public plan that doctors are forced to participate in.
Two current public plans many doctors deal with are Medicaid, which covers people who are impoverished or disabled, and Medicare, which covers people over the age of 65.
Doctors' main complaints with the two programs have to do with the difficulty in getting reimbursed and rates of reimbursement, which they say sometimes do not even cover the cost of treatments. Those costs are then passed to patients who use private insurance.
For this reason, some doctors do not take patients who use Medicare or Medicaid. The concern over a public plan is that doctors' will be forced to treat patients whose costs will not be covered.
The other concern is that such a plan would be able to set rates throughout the country because of its size, and those rates would be similar to those of Medicaid and Medicare, thus creating a financial problem for doctors -- one they feel would be exacerbated if private insurers were driven out of business. (A step the recent ABC News poll said erases favorable public sentiment for a public plan.)
According to a March 2009 study by the Medicare Payment Advisory Commission, orMedPAC, an independent body that advises Congress on Medicare issues, despite concerns about finding doctors enrolled in Medicare, fewer than 2 percent of enrollees were searching for a new primary care physician and could not find one.
However, the problem of physicians not accepting Medicare is clearly understated.
According to the Center for Medicare and Medicaid Services, 94.8 percent of family practice physicians enrolled in Medicare accepted Medicare reimbursement.
However, that number means that 5.2 percent of physicians who enroll in Medicare can still require some payment beyond what Medicare provides.
Additionally, the figure does not include physicians who do not accept Medicare at all. According to the American Academy of Family Physicians, there were 100,431 family physicians practicing in 2006. Since the CMS numbers only include the 86,164 physicians already enrolled in Medicare, that means more than 14 percent of family physicians did not accept Medicare at all in 2006.
It's still unclear how the health care reforms will be paid for.
One possibility, as mentioned before, is taxing health care benefits received through work. This appears to be an unpopular proposal, with 70 percent opposed to a tax on benefits exceeding $17,000.
Another proposal has been increased taxes on households with income above $250,000, an idea that has 60 percent of people supporting it.