Walgreen Co. said it will stop filling Medicaid prescriptions at about half of its pharmacies in Washington next month because of continued reimbursement reductions.

Walgreen’s, the largest drugstore chain in the country, said in a statement Wednesday night that it will urge state lawmakers during the legislative session to adopt ways to lower the state’s prescription drug costs without further harming the ability of pharmacies to conduct business in Washington.

The company said its decision will affect 64 of its 121 pharmacies beginning Feb. 15.

Medicaid is the federal/state insurance program for the poor and provides a means for thousands of people to obtain medical care and prescription drugs that would otherwise be too expensive.

The programs have been targeted for cuts because of soaring costs and state budget problems. Pharmacies sued last year to stop the state from cutting its reimbursement rates. The state had hoped the reduction would steer pharmacies toward generic drugs to fill Medicaid prescriptions.

Walgreen’s made similar threats last April, when it said it might quit filling Medicaid prescriptions at many stores, including four in Spokane County.