Approximately two-thirds of Americans have less than $100,000 saved for retirement, according to a report from the Employee Benefit Research Institute, and 26% of those people have less than $1,000 stashed away.

However, most workers aren't making any moves to save more. In fact, only 29% of U.S. adults say they increased their retirement fund contributions this year compared to last year, a survey from Bankrate found. The most common reason survey participants gave for not saving more, though, might be surprising.

Person handing over hundred-dollar bills.

Image source: Getty Images.

Why aren't workers saving more?

Among those who haven't increased their savings rate, the most common reason workers gave was that they feel comfortable with their current savings. Older workers were more likely to feel this way than younger workers, which isn't necessarily a surprise since older workers likely have more saved. But just because people are feeling confident about their savings doesn't necessarily mean they're on track to retire comfortably.

If you have hundreds of thousands of dollars stashed for retirement, you might be confident that you've got plenty of cash to last the rest of your life. But your golden years might be more expensive than you expect, and today's workers will need to work harder to prepare for retirement than previous generations did.

Pensions are virtually nonexistent these days, and the average Social Security check comes out to just $1,471 per month -- or $17,652 per year. There's also a chance that benefits might be reduced in the next couple of decades, as baby boomers are retiring by the thousands and living longer, and the Social Security Administration is facing a cash shortage.

If benefits are reduced and you don't have a pension to rely on, that means your savings will have to cover the bulk of your retirement expenses. If you're spending, say, $40,000 per year in retirement and you live for another 20 years after you leave your job, that's a total of $800,000 -- not accounting for inflation costs. Retirees are also more likely to face ballooning healthcare costs and long-term care expenses, which can increase your total expenses by hundreds of thousands of dollars.

How to prepare for rising retirement costs

One of the best things you can do to prepare for retirement is to simply arm yourself with as much knowledge as possible about what to expect. If you go into retirement thinking that Social Security will cover all your expenses, you won't pay a dime for healthcare costs, and you won't need to worry about long-term care, you could be in for a rude awakening later in life. But if you're aware of these costs and are adjusting your retirement plan to account for them, you'll be in much better shape.

First, make sure you're preparing for all your everyday living expenses. Your cost of living could increase or decrease in retirement depending on how your lifestyle changes, so if you're planning on living out your bucket list and traveling the world, make sure you're budgeting for those expenditures.

Next, consider how much help you'll be receiving from Social Security. You can check your future benefit amount online by creating a my Social Security account. Here you'll be able to find your statements and see what your benefits will look like based on your real earnings. When you know roughly how much you're going to be spending in retirement and how much you'll receive in benefits, you can figure out how much money will need to come from your personal savings each year.

Finally, don't forget to factor healthcare and long-term care into your retirement budget. Medicare doesn't cover everything, and the average retiree spends around $4,300 per year on out-of-pocket healthcare expenses, according to a study from the Center for Retirement Research at Boston College. Long-term care is also incredibly expensive, with the average semiprivate room in a nursing home costing more than $6,800 per month, according to the U.S. Department of Health and Human Services. Make sure you're either building these costs into your retirement budget or opting for another form of protection, like long-term care insurance. Even with insurance, though, premiums can be hefty -- so that's another cost you'll need to consider in retirement.

If you're confident about your retirement savings, that's not necessarily a bad thing. But if you're feeling confident because you don't fully realize how expensive retirement is, you might be underpreparing without realizing it. The more aware you are about how much retirement will cost, the better chance you have at enjoying your golden years comfortably.