Amid further delays for consumers, California's two largest health insurers extended payment deadlines once more for people who signed up for Jan. 1 coverage through the Covered California exchange. Anthem Blue Cross, a unit of industry giant WellPoint Inc., said it is giving new enrollees until Jan. 31 to pay their first month's premium. Kaiser Permanente, the state's largest HMO, extended the deadline to Jan. 22. Wednesday remains the official deadline for other policies purchased through the Covered California exchange, but its 11 insurers are free to grant extra time, and customers are urged to check with their specific health plan. These new dates also apply to coverage bought outside the exchange.