LOS ANGELES, Calif.–More than 100,000 Anthem Blue Cross customers statewide could end up being part of a class-action lawsuit brought by three individual policyholders and the nonprofit group Consumer Watchdog targeting the insurer’s May 1 increases to annual deductibles and other costs.

The suit, filed Monday in Los Angeles Superior Court, also targets other recent changes that allow Anthem to alter any terms of individual policyholders’ contracts on 60 days notice, including which health care services and benefits are covered, according to Consumer Watchdog.

The plaintiffs are David Jacobson of Santa Monica, Janet Kassouf of Hayward and Alison Heath of San Francisco. Premiums for all three increased by more than 20 percent on May 1, according to the complaint. They are seeking to add additional policyholders as plaintiffs to their case.

“When Blue Cross changes annual deductibles and other costs and coverage at a whim, the result is a moving target,” said attorney Jerry Flanagan of behalf of Consumer Watchdog.

“Consumers are left with no certainty about what they will have to pay and what coverage they’ll receive,” he said. “When consumers purchase health insurance, they carefully consider the price they’ll pay and the coverage they’ll receive. If Blue Cross is allowed to boost profits by changing prices and reducing coverage every two months, then the contract is worthless.”

Darrel Ng, a spokesman for Anthem Blue Cross, said the company does not comment on litigation. However, he said Anthem “works diligently to slow the increase in medical costs so we can keep health insurance affordable for as many Californians as possible. Health plans are highly regulated in the state, and all changes were made with the knowledge and approval of state regulators.”

Consumer Watchdog alleges that by making the changes to consumers’ health insurance contracts, Anthem breached those agreements and violated provisions of state law barring deceptive and misleading insurance policies, as well as other laws barring “unconscionable” contract terms.

The lawsuit targets two changes that Consumer Watchdog said render the contracts “illusory.” In February, according to the complaint, Anthem sent its California customers a letter notifying them that as of May 1, the company would increase annual deductibles and other yearly out-of-pocket costs, including co-pays and the total amount policyholders must pay out of pocket each year.

In May, Anthem implemented the mid-year increases announced in February and sent a notice to customers that as of Aug. 1, it could make changes to any terms and conditions of consumer contracts, including which health care services and benefits are covered, on 60 days notice, according to Consumer Watchdog.