Cal. INS § 10172.5

(a) Notwithstanding any other provision of law, each insurer admitted to transact life insurance, credit life insurance, or accidental death insurance in this state that fails or refuses to pay the proceeds of, or payments under, any policy of life insurance issued by it within 30 days after the date of death of the insured shall pay interest, at a rate not less than the then current rate of interest on death proceeds left on deposit with the insurer computed from the date of the insured’s death, on any moneys payable and unpaid after the expiration of the 30-day period. This section shall apply only to deaths of insureds which occur on or after January 1, 1976.

(b) Nothing in this section shall be construed to allow any insurer admitted to transact life insurance, credit life insurance, or accidental death insurance in this state to withhold payment of money payable under a life insurance policy to any beneficiary for a period longer than reasonably necessary to transmit that payment. Whenever possible payment shall be made within 30 days after the date of death of the insured.

(c) In any case in which interest on the proceeds of, or payments under, any policy of life insurance, credit life insurance, or accidental death insurance becomes payable pursuant to subdivision (a), the insurer shall notify the named beneficiary or beneficiaries at their last known address that interest will be paid on the proceeds of, or payments under, that policy from the date of death of the named insured. That notice shall specify the rate of interest to be paid. In any case where the notice required by Section 249.5 of the Probate Code has been given to a life insurer, that insurer is not required to provide the notice required by this section until after it has been notified that a child has actually been born within two years of the death of the decedent. The obligation shall be deemed satisfied by giving notice to the person who first provides proof to the insurer that the child has been born alive.

(d) This section shall not require the payment of interest in any case in which the beneficiary elects in writing delivered to the insurer to receive the proceeds of, or payments under, the policy by any means other than a lump-sum payment thereof.