Haraz N. Ghanbari/AP

President Obama sought to reassure older Americans on Tuesday that health reform would not disrupt their Medicare coverage or force them to change doctors.

The president said he wants to change the health care system so that every American can enjoy the health and financial security Medicare currently provides to people ages 65 and older.

Mr. Obama made the comments during a televised forum hosted by the AARP. Exactly 44 years ago on Tuesday, the president pointed out, Congress passed the legislation creating Medicare.

To illustrate what he said were misunderstandings surrounding health reform, Mr. Obama quoted from a letter he received recently from an elderly woman: “I don’t want government-run health care,” she wrote. “I don’t want socialized medicine, and don’t touch my Medicare.”

One caller said that one fear she hears often among friends is that the government will start telling doctors what kind and how much health care seniors are allowed. “When I’m 80, will I still be able to get a hip replacement?” the woman asked.

The president replied that the federal government is not going to ration care by deciding which seniors should get hip replacements. The government does want to learn more about what treatments and conditions work best and to use that information to guide doctors, he added.

Another caller referenced her 56-year-old brother who wants to buy health insurance but cannot because he has pre-existing conditions. She asked how health reform would help him.

The federal government would require insurance companies to provide coverage to all who want it, Mr. Obama said. In addition, he said he wants to create health insurance exchange where people can compare and shop for coverage just like members of Congress.

Another caller asked about the costs of health reform and the costs of doing nothing.

The price tag of the current health reform bills, the president said, is about $1 trillion over the next ten years. Doing nothing, he said, will result in uncontrolled cost increases and increasing numbers of people without health insurance.

AARP has posted video of the event here.