At least 35 states and the District of Columbia have joined in efforts to look at how life insurers determine whether insureds have died and how they go about locating policy beneficiaries.

Two of the states – California and Florida – have scheduled hearings for May on the procedures MetLife Inc., New York (NYSE:MET), is using to track down life insurance beneficiaries and to determine whether policies have lapsed because the insureds have died.

Florida regulators will hold their hearing May 19, and California regulators will hold their hearing May 23.

Florida regulators also have sent a subpoena asking Nationwide Financial Services Inc., Columbus, Ohio, to participate in the Florida hearing, officials say.

Florida’s probe centers around whether some insurers use a Social Security death database to determine whether the owners of annuities have died but fail to use the database to find out whether their life policyholders have died.

California Controller John Chiang, who has announced a 23-state settlement in connection with concerns about unclaimed property practices at a unit of Manulife Financial Corp., Toronto (TSX:MFC), says the investigations began when his office launched an audit in 2008.

Officials in the Chiang’s office have reported in preliminary audit findings that a unit of MetLife may have failed to pay life insurance policy benefits to named beneficiaries or the state after learning that an insured had died.

Chiang says MetLife sold a large number of industrial life policies to working-class people in the 1940s and 1950s.

“The controller’s unclaimed property audit indicates that MetLife did not take steps to determine whether policy owners of dormant accounts are still alive, and if not, pay the beneficiaries, or the state if they cannot be located,” Chiang says in the statement.

MetLife “will fully cooperate with the California investigation,” MetLife spokesman John Calagna says in a statement. “MetLife’s first priority is to keep its promises to its policyholders,” and the company “has a strong history of taking proactive measures beyond those required by law to improve its ability to make prompt payment of life insurance benefits to the correct beneficiary upon notice of death.”

Since 1989, MetLife has established policies and programs designed to “encourage family members to help the company to identify and locate policy owners and beneficiaries for industrial life policies issued from 1879 to 1964,” Calagna says.

More recently, Calagna says, MetLife has “sought to ensure the quality of its address records in connection with its demutualization in 2000, this time using improved technology and databases to confirm addresses.”

MetLife also launched locator programs in 2006 and 2007, Calagna says.

As a result of the latest investigation, “MetLife will repeat and expand its use of its electronic death master file to identify potentially payable life insurance policies in 2011 and is implementing a process to repeat the match process annually,” Calagna says.

Nationwide has responded to the Florida hearing announcement by noting that it pays about a billion dollars in life and annuity death benefits each year.

“We strive to ensure compliance with all laws and regulations governing our products and services,” the company says. “We will continue to cooperate with the state inquiries on this matter and are committed to serving the needs of our customers and their families.”