U.S. employers covering care in Mexico.

SAN DIEGO - With tens of thousands of workers legally commuting from Mexico to work in the United States each day, a growing number of U.S. employers are turning to health plans that provide medical care on the south side of the bustling border.

Such plans are carving out a niche by making private health coverage available to dependents who live in Mexico and cannot easily cross the border to receive treatment in the United States. While Mexican employees may have immigration documents allowing them to work or travel in the United States, their family members may not.

In addition, the plans are popular because some Mexican employees who work and live with their families in the United States prefer obtaining medical treatment in Mexico because of cost savings and cultural sensitivity, according to employers.

Many of the new plans providing health care in Mexico are not regulated by insurance officials in either country.

Officials at the Comision Nacional de Seguros y Fianzas in Mexico City say that under pressure from their country's insurers, they are considering adopting regulations for HMO-type companies.

A spokesman for the California Department of Insurance said the department has licensed a couple of plans that sell their service to employers in the United States and cover treatment south of the border.

For example, Pasadena, Calif.-based Paula Insurance Co., which specializes in coverages for the agricultural industry, this year announced that under a California-approved workers comp plan, it is offering injured workers treatment at a hospital in …