Through the first half of the 20th century, a long and comfortable retirement was something few workers experienced. Pensions were not common, Social Security was just getting started, and anyway, most workers died on the job or shortly after retiring.

Then things changed. Social Security flowered. Unions extracted better pensions and other benefits from employers. New federal laws made if difficult for employers to renege on promised benefits and provided government-backed insurance for pensions if employers went broke.

Now, that latter period, especially the years from about 1975 to 2000, is beginning to look like the golden age of retirement in America. In other words, those were the good old days, and if you're still working, there's a good chance you've missed out.

The retirement that looms for many of today's workers is likely to be quite different. While some will still have that magic combination of Social Security, a private pension, a 401(k) and company-sponsored retiree medical insurance, their numbers are shrinking steadily.

The conclusions of experts who study the situation are depressingly uniform. Retiree medical insurance is fading fast. Private pensions -- the kind that provide a lifetime stream of income -- have declined drastically over the past two decades, though they are slipping more slowly now. Social Security's future is problematic, and workers are not doing well in their 401(k)s.

The do-it-yourself trend in retirement -- and the low participation in 401(k) and similar plans -- is the heart of the problem, and has been getting some attention lately. But not widely appreciated is the impact of the disappearance of retiree health insurance.

A new study finds that medical costs can equal 20 percent of pre-retirement income for a worker who retires at 65 and who has no employer health care benefits. In other words, a worker who has savings and pension income adequate to replace all of her pre-retirement income is really 20 percent short of that unless she has some form of employer medical subsidy. And that assumes Medicare eligibility. Workers retiring early without employer medical are projected to have only 59 percent of pre-retirement income left after medical expenses.

The study, by Hewitt Associates, a benefits-consulting firm based in Lincolnshire, Ill., notes that other research indicates that retirees need to have enough resources to replace 85 to 90 percent of their pre-retirement income to maintain their standard of living.

Hewitt found that only workers who have the entire package, including a traditional pension and retiree medical, seem likely to reach that level.

Those who have only a 401(k) and Social Security start off at 80 percent of pre-retirement income and go down from there, depending on whether they have employer medical and how generous it is. In fact, the study projects that retirees with only Social Security and a 401(k) and no employer medical benefits will be left with only 57 percent of their pre-retirement income to live on.

In fact, the assumptions in the study are such that, if the findings are correct, many workers will be even worse off. The retirement income projections assume, among other things, that the worker retires at 65, lives 20 years in retirement and draws down 100 percent of her 401(k) balance during that time. Since that's right around the actuarial life expectancy of retirees today, all those who live longer -- and half can expect to -- will exhaust their 401(k) funds before their death.

Lori Lucas, director of participant research at Hewitt, call the findings "a wake-up call" for employees.

"Employees need to make their 401(k) programs work harder for them," and they "need to anticipate the potential cost of paying for much of their retiree medical themselves," she said.

Lucas added that essentially no employer today thinks seriously of starting a traditional pension. Companies argue that such pensions are too volatile in their funding requirements and that their competitors don't have them. Indeed, those that still have traditional pensions "are wondering if someday their [retirement plans] will look like this," with only a 401(k) plan.

The study covered 62 large companies with nearly 1 million employees.

Employers' response to Hewitt's findings is that they need to increase 401(k) plan participation and help workers figure out how much they should be saving. But don't look for additional financial help.

For many workers, the answer is going to be simple and not very pleasant: They will have to work longer and be retired fewer years. Hewitt found that working until age 67, instead of 65, and contributing an additional 2 percent of pay to a 401(k) would allow many younger workers to reach 80 percent of pre-retirement income, even with health care costs included.

And, while it's hard to do with jobs in short supply in many parts of the economy, workers lucky enough to have a choice of employment should look hard at potential employers' pension offerings, give weight to the best one, and let the companies know that a good pension is a serious factor in choosing among them.

As predicted, interest rates on government-guaranteed student loans fell to historic lows last week. The new rates, which are in effect from July 1, 2004, through June 30, 2005, are:

* Federal Stafford Loans during in-school, grace and deferment periods: 2.77 percent.

* Federal Stafford Loans during the repayment period: 3.37 percent.

* Federal Parent Loans for Undergraduate Students (PLUS): 4.17 percent.

These rates will be adjusted again next year and may rise. However, students with multiple loans may be able to consolidate them, locking in a low fixed rate.

Thinking of donating your car to charity? After congressional hearings pointing to extensive abuses of these programs, the Internal Revenue Service is reminding everybody to play by the rules.

To that end, the agency is now offering two new publications, one for donors and one for charities, spelling out who has the right to do what and with which and to whom.

Publication 4302, "A Charity's Guide to Car Donations," and Publication 4303, "A Donor's Guide to Car Donations," were written in conjunction with state charity officials. They are available at www.irs.gov.