President-elect Barack Obama and the new Democratic Congress must repeal a terrible rule change that the Bush administration imposed while packing up.

This rule change, which takes effect Jan. 25, allows states to force people who are on Medicaid to pay more for health care services. This is a grave threat to the good health of millions of poor Americans — and millions of Americans with disabilities.

Medicaid recipients are the poorest Americans. They must have very little income and very few assets to be eligible for coverage.

But the Centers for Medicare and Medicaid Services, the federal agency that administers the Medicaid program, made no secret of the fact that a major intent of the rule is to make health care less affordable for Medicaid recipients so they will not seek medical attention as often.

“We assume there would be declines in utilization as some enrollees subject to new cost sharing requirements choose to decrease their use of services,” the Centers for Medicare and Medicaid Services wrote when the rule change was published in the Federal Register.

Pricing health care beyond the range of Medicaid recipients will no doubt cause them to cut back on preventive measures and ignore some conditions that should be treated right away.

Attacks like this one on the lowest-income Americans disproportionately affect people with disabilities. According the U.S. Census Bureau, 27 percent of Americans with significant disabilities live in poverty, compared to 9 percent of nondisabled Americans. About 5 million Americans with disabilities under age 65 are covered by Medicaid, according to the Kaiser Family Foundation.

Will the Obama administration take action to reverse this cynical, harsh shift in Medicaid policy?

To do so, he must stand up for the poor and for people with disabilities, two overlapping groups he mentioned too infrequently during the campaign, as he spoke incessantly about the need to lift up the middle class.

Democrats in Congress must rise to this moral challenge, as well.

Medicaid is a lifeline. We can’t let it be cut.

Mike Ervin is a Chicago-based writer and a disability-rights activist with ADAPT (www.adapt.org).