SPRINGFIELD, Ill. (AP) — Hundreds of thousands of low-income Illinois residents will move into managed care health plans Jan. 1.

Medicaid coverage administered by the Illinois Department of Healthcare and Family Services will expand dramatically Monday.

HealthChoice Illinois adds 800,000 Medicaid clients to what’s intended to be a more efficient, cost-effective system of health care delivery.

The four-year deal will cost more than $60 billion — a 50 percent increase from the current setup. But Gov. Bruce Rauner’s administration contends it will save $1 billion over four years because of lower reimbursement rates insurers accepted to be able to participate.

But critics question whether they’re so low they threaten viability. Iowa’s Medicaid managed care plan suffered a major disruption when it lost a major insurer for that reason in November.