Saving for retirement isn’t easy, but figuring out how to manage your money after retirement is pretty tough, too.

While you’ve had lots of practice at saving money, now you have to figure out how to make that savings last for the rest of your life—and since you may not have much in the way of income, you don’t have a big margin for error.

That first year, in fact, may be the most difficult of them all. Flush with excitement, many new retirees rack up big bills. “Typically, you will see more spending in first year,” says Greg Hammer, president of Hammer Financial Group in Schererville, Ind.

Below are some of the biggest pitfalls to watch out for.

Treating yourself a little too well

Retirement is here! Time to treat yourself, right?

“People say, “‘I’ve been waiting to do this. It is on my bucket list,’” says Rich Ramassini, director of strategy and sales performance at PNC Investments. Unless you have a solid source of post-retirement income, however, a big initial spending bump can be a major threat to your retirement security.

That’s not to say you need to practice full-on austerity. If you’ve always wanted to take a month-long trip, or spend an extended summer at the beach, that’s okay. “As long as you factor that in, it’s not a problem,” says Hammer.

In fact, Hammer says, you can usually spend as much in your first five years of retirement as you spend in the 10 years after that. A financial planner can help you run the numbers and come up with a target annual budget for now and the future.

Not planning for unexpected expenses

Many financial planners recommend that working people keep three months of living expenses in a savings account, in case of a sudden job loss, medical crisis or other unexpected expense.

But while you don’t have to worry about job loss after retirement, the need for a cash cushion is, if anything, even more critical, says Eric Bailey, of Bailey Wealth Advisors in Silver Spring, Md.

“You are always going to have some kind of unforeseen expense, whether its health care or your house.”
Financial planner Eric Bailey

“You are always going to have some kind of unforeseen expense, whether its health care or your house,” he says, “Emergency cash is the buffer that allow you to cover the debt without going into your investment portfolio or going into debt to cover that.”

Taking Social Security too early

About a third of people opt to take Social Security as soon as they qualify, at age 62. Some do it because they have to, and others do it because they don’t trust that Social Security will be around when they are retired.

But if you start taking benefits at 62, you’ll be locking in a benefit that is 30% lower than what you would receive at full retirement age (65 or 66, depending on when you were born).

Every year you wait after full retirement age, your benefit increases by 8%. If possible, you may even want to hold off until age 70, when benefits are highest.

Letting emotions rule your investing decisions

Even those who live by the mantra of “set it and forget it” during their wealth-building working years sometimes run into trouble post-retirement, says Philadelphia financial planner Kyle Rolek, “People have more time in retirement to watch the news, listen to ‘market experts,’ and ‘study the markets,'” he says.

Every year you wait after full retirement age to take Social Security, your benefit increases by 8%.

But if that habit translates into yanking funds in and out of accounts, or moving into investments that may be too risky for them at this time in their lives, “It’s an expensive hobby,” Rolek says.

On the flip side, retirees who feel anxious about losing their money in the market sometimes become too conservative, keeping too much of their savings in cash or fixed-income investments. But if your retirement spans several decades, you’ll need the higher returns of stocks to grow your savings.

Especially if your spending start to look different than you’d planned, it may be worth sitting down with a financial advisor to make sure your investment strategy still matches your goals.