Definitions of the term "voluntary benefits" are about as varied as the products that fill this niche market.

MetLife, for example, considers as voluntary benefits "any elective benefit program in which employees are required to pay more than half of the cost," according to Maria R. Morris, executive vp of employee benefit sales in New York.

Chattanooga, Tenn.-based UnumProvident Corp. defines them as any benefit that has an employee contribution, according to Mike Simonds, vp of marketing and product development based in Portland, Maine.

Others, such as Watson Wyatt Worldwide Inc., define as voluntary those benefits to which employers do not contribute, according to Tom Billet, a senior consultant based in Stamford, Conn.

By contrast, Aon Consulting, a division of Chicago-based broker Aon Corp., defines as voluntary benefits any type of product that is offered as a supplement to an employer's core benefits program and that is paid for via payroll deduction, according to Garry Sullivan, senior vp and national practice leader for elective benefits based in Chicago.

If that broad definition is used, then voluntary benefits would include such products as long-term disability and term life insurance buyups and vision and dental plans, as well as personal lines insurance such as home, auto and pet insurance.

Kansas City, Mo.-based Assurant Employee Benefits addresses the confusion by dividing its marketing of ancillary benefit products into two segments: true group and voluntary. True group products are those to which employers contribute either all or a portion of premium; voluntary are entirely employee-paid. Both types of products are underwritten on a group basis.

The type of voluntary benefits products to which employers are likely to contribute varies widely, according to Barbara Howe, vp of the consumer segment at Hartford Life, a unit of The Hartford in Simsbury, Conn. "Most companies will provide some payment toward medical, dental and life, and then it's really all over the board," Ms. Howe said.

For example, most employers typically pay for LTD coverage, providing up to 50% of an employee's salary and then give employees the option of buying additional coverage to replace up to 70% of income.

In addition to LTD coverage, many employers provide a basic life insurance policy, usually the equivalent of one year's salary, allowing employees to purchase additional multiples at their own cost, experts say.

And 99% of employers that offer dental insurance usually contribute to its cost, according to Mr. Billet.

But rarely do employers contribute to personal lines coverage, such as home or auto.,

Though, "once in a while, if a company is taking away company cars, they will sometimes fund the premium," noted Rob Maloney, vp and manager of affinity marketing at Liberty Mutual Group in Boston.