In August, President Bush signed a bill making major changes to retirement plans operated by companies. These pension plans provide defined payments and services, called benefits, to retired workers. The new law gives workers a better chance to get the retirement benefits they have earned.

The new law requires most private companies that provide pensions to have enough money to pay for one hundred percent of benefits for workers who retire. Companies have seven years to fully fund their pension plans. The air travel industry has an extra ten years to do so.

The new law also makes it easier for workers to save money in other kinds of retirement plans. 

Defined contribution plans do not offer guaranteed benefits. Instead, employees, and usually their employers, add money to an investment plan that is not taxed. When workers retire, they can withdraw money from the plan. 

One example is the four-oh-one-K plan. Part of the new pension law makes it easier for employers to offer investment advice to employees with four-oh-one-K plans.

The new law also makes permanent a law that increases the amount of money that people can put into an Individual Retirement Account, or I.R.A. Workers can save money in I.R.As tax-free until retirement.

Experts say many current pension plans do not have enough money to provide the benefits promised to workers. Total pension deficits are estimated at between three hundred and four hundred fifty thousand million dollars.

The Pension Benefit Guaranty Corporation rescues pensions of failed companies or businesses that cannot meet their plan's requirements.

Earlier this week, the P.B.G.C. took over the pensions of almost two thousand workers and retirees for Oneida Limited, a maker of cooking tools. The P.B.G.C. says it pays monthly benefits to almost seven hundred thousand retirees in about three thousand six hundred pension plans. 

Experts say the new pension law shows how much retirement has changed in America. In the past, most employees expected to retire from a job they held for most of their working life. Today, workers need pension plans that can be moved from one employer to another.