The Wall Street Journal: Whatever Happened to That Old 401(k)?

Suspect you may have lost track of a 401(k) retirement account or pension benefit?

You aren’t alone.

As Americans jump from job to job, they are leaving more 401(k)-style accounts and pension benefits with ex-employers. Some lose track of the money, forfeiting a piece of their retirement security.

While no one keeps exact tabs on the number of lost retirement accounts, human-resources consulting firm Aon Hewitt estimates that as many as 30% of all pension accounts may ultimately fall into this category—either because a plan can no longer locate former employees who move or change names, or because a participant forgets that he or she is entitled to benefits or cannot find a past employer that changed it.

When the U.S. Department of Labor recently studied the public filings of 50 large pension plans in the six states that fall within its Philadelphia office’s jurisdiction, it found more than 70,000 participants older than 65—the age at which pension plans typically start paying benefits—who were entitled to “well over $100 million in annual benefits” but weren’t collecting them, says Michael Schloss, director of the Philadelphia Regional office.

When the agency contacted over 5,000 of these people, it discovered “a very large percent didn’t know they even had a pension,” Mr. Schloss says.

Experts say the problem is likely to get worse. A 2014 report from the U.S. Government Accountability Office says the growing use of automatic enrollment in 401(k) plans and shorter job tenures is contributing to participants having inactive 401(k) accounts.

U.S. Senators Elizabeth Warren (D., Mass.) and Steve Daines (R., Mont.) recently introduced a bill to use Internal Revenue Service data to start an online database that individuals could use to look up their pension and 401(k)-style retirement accounts

Meanwhile, what can you do if you think you lost track of an account or benefit?

The first step is to find your old employer and send a letter or email requesting information about your retirement benefit, says Joseph Adams, a lawyer who specializes in retirement plans at McDermott Will & Emery LLP.

If the company no longer exists or you just can’t find it, free help is available from sources including the Labor Department and six nonprofit pension-counseling centers funded by the U.S. Department of Health and Human Services’ Administration for Community Living (See table). The Pension Benefit Guaranty Corp., or PBGC, provides help locating traditional pensions.

These services can tap into public databases that list incorporations and bankruptcies and may be able to help participants dig up a plan’s most recently filed Form 5500, the annual report that must be filed with the IRS, PBGC and the Labor Department. This form contains the plan’s contact information and the employer’s identification number, which can be used to locate any plan that inherited the assets in a merger, acquisition or sale, says Judith Starr, general counsel at the PBGC.

Recently filed 5500s can be found on websites such as freeerisa.comand It also is possible to request older filings.

If a former employer terminated its defined benefit pension plan, check with the PBGC. The agency maintains a searchable database of missing participants in the underfunded pension plans it takes over, as well as pension plans terminated by employers.

Finding a lost 401(k) account can get tricky if the balance in the account is $5,000 or less. Federal law allows plans to transfer balances of up to that size to an individual retirement account at a financial-services firm—without the missing participant’s consent. To find it, you can call or search the online databases of companies that accept transfers of small balances from 401(k) plans. They include Millennium Trust Co., PenChecks Trust, Inspira and Retirement Clearinghouse LLC.

When a company terminates a 401(k) plan, it must transfer all accounts to participants. If a participant can’t be located, the firm can send the money to an IRA, bank account or a state’s unclaimed property fund. Some plans may transfer the 401(k) accounts of missing participants older than 70½—the age at which the IRS requires people to start taking withdrawals—to state unclaimed property funds. Search the state where you lived or worked or where the plan’s administrator is incorporated, advises Tami Salmon,associate general counsel at the trade group Investment Company Institute.

Starting in 2018, the PBGC will accept transfers of missing participants’ accounts from terminating 401(k) plans, says Ms. Starr. When the participants are found, it will pay them that money plus interest. The agency also plans to launch a registry of terminated 401(k) plans that sent money elsewhere, so missing participants can more easily find their accounts. Participation by employers is voluntary.

More complicated still are situations in which former employees are denied pension benefits they believe they are owed.

In such a situation, “I wouldn’t assume a company’s records are perfect,” says Jeanne Medeiros, director of the Pension Action Center in Boston, a nonprofit that helps reunite people with their retirement funds.

To prove eligibility for pension benefits, participants may need to dig up old employment records including W-2 forms and notifications from a pension plan of a vested benefit, Ms. Medeiros says. Those without these records can order—for $136 via Form 7050—a detailed earnings report from the Social Security Administration that provides a year-by-year record of an individual’s employers and earnings.

Also available from Social Security is a “Notice of Potential Private Pension Benefits,” which lists every company that reported to the IRS that you have a pension benefit or 401(k) account.

If you believe you are owed a pension but your former employer claims you cashed it in, you may need to produce old tax records, says Ms. Medeiros.