Wal-Mart's critics are often appalled by the company's health insurance coverage, but the facts don't always justify the rants directed against the company.

Detractors point out that Wal-Mart covers only 48 percent of its employees. But according to the Employee Benefit Research Institute, in the retail sector overall only 45 percent of workers receive health coverage from their own employer. Still, why do more than half of Wal-Mart's employees opt out of the company's health insurance?

For one thing, part-time workers who make up 25 percent of Wal-Mart's workforce are not eligible until after two years. Then there is the cost. Wal-Mart pays 67 percent of the cost of health insurance for employees, about equal to the retail industry average of 68 percent for family coverage—but, for individual health insurance, far below the 77 percent that retailers contribute on average.

Many employees opt out because they are otherwise covered. The company says that two-thirds of its employees are second-income providers, college students, and senior citizens. Many of these have health insurance through their spouse's employer, parent's plan, or retirement and Medicare programs. Thus about 40 percent of the company's workers are covered apart from Wal-Mart's plan.

Hence the company asserts that close to 90 percent of its employees have health insurance by one means or another. Deductibles are $1,000 for a plan with a low premium, which does not include routine treatments such as flu shots and child vaccinations. Wal-Mart's health insurance emphasizes protection for catastrophic health expenses such as cancer treatment.

Health-care premiums for U.S. employer plans increased 11.2 percent in 2004, the fourth consecutive year of double-digit ...