Wal-Mart Stores Inc. says it has succeeded at increasing the percentage of workers who are signing up for medical insurance.

During the fall 2006 open enrollment period, 636,391 employees signed up for Wal-Mart health plans, up about 8% from the number who signed up for Wal-Mart coverage a year earlier, according to Wal-Mart, Bentonville, Ark.

The number who signed up for “associate plus children” coverage increased more than 11%, Wal-Mart says.

About 9.6% of Wal-Mart employees lack health coverage, but only 3.1% get health coverage from Medicaid or from state health insurance programs other than Medicaid, Wal-Mart reports.

About half of the new Wal-Mart plan enrollees were uninsured before they signed up for Wal-Mart plan coverage, and 7.8% were enrolled in Medicaid plans, Wal-Mart says.