On Medicaid’s 40th anniversary the lesson from the program worth remembering is not just that it has provided access to medical care for millions of low-income Americans, but that it has produced results, improving health and saving money. As Congress tries to chop $5 billion or $10 billion from this valuable means to better health for the poor, it should take care not to save money in the next budget by costing future budgets and the health of Americans considerably more.

Nearly a decade ago, the Quarterly Journal of Economics published a report showing the expansion of Medicaid for low-income children lowered their death rate by 5 percent. Since then, other studies have shown Medicaid reduces infant mortality, drops the number of hospitalizations for those covered and helps keep patients’ high blood pressure under control. It also is responsible for reducing the amount of charity care absorbed by hospitals and those who are privately insured and is the nation’s major source of nursing-home funding.

Medicaid began as one of many Great Society programs, along with Medicare, championed by President Lyndon Johnson. Its promise was to raise the quality and breadth of care for those who could not afford it and, in millions of instances, it has succeeded and continues to provide cost-effective care. Nevertheless, like any large and sprawling program it requires periodic reform and a governors’ movement to overhaul the system earlier this year was welcome.

That reform, however, coincided with more tax cuts in Congress that require cuts in the expected growth of health care and other social programs. The budget calls for $10 billion in total cuts over five years; Congress has yet to determine which programs will be trimmed but Medicaid is the most likely target.

Taken together, the governors’ reform and the program cuts led Secretary Michael Leavitt of Health and Human Services to establish a commission that will submit two reports over the next six months on changes to eligibility and benefit design, how to expand the number of people covered and how to provide long-term care, among other topics. Vice chairman of the commission is Angus King, former governor of Maine.

The National Governors Association did not reach conclusions that would improve the performance of the Medicaid system, and instead pressed for more flexibility for states to design their own systems. That is part of the problem with Medicaid now, with states viewing the Centers for Medicaid & Medicare Services as a funding source to balance their budgets. The commission needs to do more careful work if it hopes to be helpful.

Medicaid has improved the chances of infants surviving and provided crucial nursing care for the elderly. It has deliverer dollars efficiently to states and reduced cost shifting to private insurers. Even as reform of this program is necessary, its reformers should recognize the important role Medicaid has played for four decades.