Editor's Note: An updated version of this article reflects a difference in the timing of Sears Holdings’ announcement. We apologize for any confusion.

Once upon a time, after you put in a long career, you could count on your employer to help you retire comfortably. That era is no more. Now, you have to do everything you can to protect yourself from the moves that many employers are making right now.

Taking away the carrot
As part of their total compensation packages, most employers offer benefits to entice workers to hire on with them. When you've received multiple job offers and are trying to decide among them, a good benefits package that includes a pension plan or a matching contribution to your 401(k) can mean thousands of extra dollars in value every year. That can make a huge difference in which job you decide to take.

Unfortunately, many employees don't realize is that their employers can change their minds about those benefits at pretty much any time. Consider some of these major hits to employees' retirement prospects:

  • Kraft Foods (NYSE: KFT), HSBC (NYSE: HBC), and Time Warner (NYSE: TWX) have all frozen their pension plans this year, leaving hundreds of thousands of employees facing diminished benefits.
  • Some employers are still cutting back on matching contributions to their employees' 401(k) accounts. Although many of those cuts in 2008 and 2009 turned out to be temporary, Honeywell (NYSE: HON) and Exelon (NYSE: EXC) rank among the companies that recently cut their employer matches.
  • Employees who retired with the promise of receiving medical benefits are seeing them taken away. In 2005, Sears Holdings (Nasdaq: SHLD) announced that it will no longer pay anything toward early retiree medical benefits, while Sunoco (NYSE: SUN) has taken away retiree medical benefits entirely.

These moves can have a huge impact on your current and future retirement plans. Because pensions generally pay their highest benefits to longtime employees, pension freezes can especially hurt. They limit the number of years of service you're considered to have worked under the plan, leading to a much lower payment when you retire. And with medical costs constantly on the rise, medical benefit limitations can mean the difference between retiring and having to continue to work.

Between a rock and a hard place
Unfortunately, this problem won't go away anytime soon. In fact, public employers, once considered havens for attractive benefits, could be the next problem areas for pensions. State and local governments are facing huge budget crunches, now that the recession has dramatically reduced their revenues. Meanwhile, public pension programs are severely underfunded. It's likely that the pension freeze and benefit reduction trends that private employers have seen for years will soon migrate to the public sector as well.

That may seem colossally unfair, especially to those workers who argue that the entire reason they took lower-paying jobs was due to benefits that are now being taken away. But as long as unemployment hovers around 10%, employees don't have the bargaining power to do much about it. Even labor unions are being criticized for wasting money on lobbying efforts and political campaign contributions, rather than providing direct assistance to their members. Without strong advocates, it's an employer's market for labor, and benefits are the easiest thing to cut.

Take charge of your future
Look at weaker job benefits from two perspectives. As an investor, reduced benefits cut costs in the short run, and as long as the weak economy keeps competition for labor at a minimum, those cuts shouldn't cause mass defections among workers desperate to hang onto any job they can get. So shareholders in companies that successfully manage and reduce their benefits costs should see higher profits (or smaller losses) as a result.

Personally, though, you need to take a look at your own benefits package. Figure out what benefits are guaranteed, and which could be changed at your employer's whim at a future date. Make the most of benefits like employer matching while they're available, understanding that once you get a match (and meet any vesting requirements), it's yours to keep. And most importantly, have a contingency plan that you can follow if your benefits change over time. That way, you won't feel the full impact of any future cuts in benefits.

Workers who've worked a lifetime for benefits only to see them cut are rightfully angry. But younger workers are learning that employers are only grudging partners in the quest to retire comfortably. If you're smart, you'll do everything you can to make that journey entirely on your own.

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Fool contributor Dan Caplinger has always milked his benefits for all they're worth. He doesn't own shares of the companies mentioned. Motley Fool Options has recommended writing puts on Exelon, which is a Motley Fool Inside Value choice. Try any of our Foolish newsletters today, free for 30 days. The Fool's disclosure policy rises from the ruins of Wall Street corruption and despair.