These days it’s not uncommon for a worker to spend his or her career at half a dozen or more companies before retiring. It’s also not uncommon for companies themselves to go through numerous mergers and ownership changes. The odds of record-keeping errors also grow as companies change hands. It’s generally easy to keep track of old 401(k) and other defined-contribution plan accounts created for you since they are your personal property. But company pension plans do not maintain separate accounts, and sometimes the plan administrators lose track of ex-employees after the company has been absorbed several times or has gone out of business. Is there anything you can do to find out if you’re entitled to a pension from an employer you left long ago?

Fortunately, there is. And it’s a good thing, too, because the amount of unclaimed pension benefits is quite large, according to the Pension Benefit Guarantee Corp (PBGC), the government agency responsible for protecting private-sector defined-benefit pension plans. The PBGC estimates more than 38,550 people are owed more than $300 million from plans that they administer, according to a Reuters report. And those plans are only the ones that have been terminated by their companies. No one is tracking missed benefits from the thousands of active company pensions.

The first step is to search the PBGC database for unclaimed benefits: http://search.pbgc.gov/mp/mp.aspx. But this database only covers plans that have been turned over to the agency. If you can’t find anything, you might try the Pension Rights Center, a nonprofit consumer organization committed to protecting and promoting the retirement security of workers, retirees, and their families. Recovering missing pension benefits for retirees is one of their biggest activities.

There are also regional organizations. The Western States Pension Assistance Project is a project of Legal Services of Northern California and the California Senior Legal Hotline. Funded primarily by a grant from the federal Administration on Aging, they provide free pension counseling and assistance to residents of California, Arizona, Nevada and Hawaii, and have helped many people obtain missing retirement benefits. You can find them at http://slh.lsnc.net/pension/. They also provide links to other regional pension assistance organizations that help people in those states or that can provide help tracking down pensions from companies previously located in those areas.

Of course, the best strategy is not to lose track of potential pension benefits in the first place. Here are some key tips:

• Hold on to any copies of annual Summary Plan Descriptions (SPD) you may have received from employers, as well as any individual benefit statements.
• Keep all your old income tax returns and W-2 forms, because these documents can help establish working histories in case a successor plan administrator’s records are incomplete or in error. If you haven’t saved them and need to document your employment history, you can order a detailed earning report from the Social Security Administration, using SSA Form 7050 at www.ssa.gov/online/ssa-7050.pdf.
• Before you leave a company, ask for written verification of your vested status with the plan administrator. Be sure to get a copy of the SPD in effect on your last day of work, because your benefits will be determined by the plan in effect on your last day. You can obtain the SPD by making a request in writing to your plan administrator. Also make sure pension managers know where to contact you, and keep them up to date if your contact information changes.

If you do have a pension at a company that is sold or goes out of business, contact its human resources department or benefits center immediately to find out what will be happening to the pension plan. Pensions are rapidly becoming a rare commodity, so make sure you take full advantage of any to which you are entitled.