A large insurer is beefing up the roster of doctors and hospitals it offers self-insured customers in New York and New Jersey.

Principal Financial Group Inc., Des Moines, Iowa, has agreed to add providers from MagnaCare Holdings Inc., Garden City, N.Y., to its Empire State and Garden State provider networks.

In related news, the UnitedHealthcare unit of UnitedHealth Group Inc., Minnetonka, Minn., says it has increased the number of hospitals in its California network to 326, from 285, and the number of doctors and other providers in the network to 49,000, from 38,000, this year through internal growth.

California insurance regulators required UnitedHealthcare to develop its own proprietary network before it approved the company’s application to acquire a large California managed care company, PacifiCare Health Systems Inc., Cypress, Calif., earlier this year.