The letter said cutting the supplement would cut payments to 2.2 million people on the lowest incomes including pensioners, sole parents, single-income families, carers and Newstart recipients.
Medicare cut payments to doctors by 5.4percentthis yearar.
The third method is to cut payments to hospitals and doctors.
Over all, those actions collectively cut payments to shareholders by $37 billion, a record.
If Medicare costs rose too much, Mr. Stark said, Congress could cut payments to private plans.
It will also cut payments into the federal employees retirement system.
He asked Congress to cut payments to states that covered children at higher income levels.
Like Mr. Obama, the association wants Congress to cut payments to private Medicare Advantage plans.
The health care law cut payments to private Medicare Advantage plans after many studies found that they were being overpaid.
That has left states to cut payments to providers and trim benefits not required by federal regulations.
Health care overhaul bills passed by the House and the Senate would cut payments to the private plans.
