More than 100 organizations are calling on lawmakers to equalize Medicaid and Medicare payment rates as part of any comprehensive health care reform bill passed by Congress.

Both of the major House and Senate health care reform bills would expand Medicaid coverage to more low-income individuals. Only the House bill, however, includes a $57 billion provision that would adjust Medicaid payments for primary care to at least 100 percent of Medicare rates.

In a letter to House and Senate leaders, 117 physician, patient and labor organizations urged Congress to "ensure meaningful access to care under the proposed Medicaid expansion by adopting the House provision to bring Medicaid reimbursement rates for primary care in line with comparable Medicare rates within four years."

"While we strongly support expanding Medicaid to extend health coverage to low income individuals, we are very concerned that failure to address reimbursement disparities will weaken an already fragile network of Medicaid providers at a time when the demand for their services will be growing," says the letter, signed by the American Academy of Family Physicians, the American College of Physicians, the American Osteopathic Association and the American Academy of Pediatrics, among others.

The letter points out that Medicaid rates average just 66 percent of Medicare rates for primary care services and are "woefully inadequate to cover the cost of providing care. The inadequacy of Medicaid reimbursement levels must be addressed in conjunction with Medicaid expansion, or we risk leaving our poorest and most medically vulnerable residents behind, despite the remarkable promise offered by health reform."