Wal-Mart, whose health coverage for employees has been a target of critics, says it will offer improved options for workers next year that include $4 generic drugs and monthly premium costs of as low as $4.36 on some of its plans.

The company drew criticism from unions — and some state lawmakers — in recent years for its coverage, which critics called unaffordable for some of its 1.3 million workers, causing them to be uninsured or enroll in programs like Medicaid.

Starting in January, workers will be able to mix-and-match up to 50 different combinations of deductibles, credits and premiums, which the company says should help boost enrollment. Last year, Wal-Mart said 43 percent of its workers had health insurance through the company, although a full 90 percent had some coverage, through spouses, parents or government.

"It's hard to see why an associate would not choose health coverage when we have plans as low as $4.36 to $7.31," says Wal-Mart spokeswoman Sarah Clark.

The new plans will offer: