Image: Worried retired couple © Abel Mitja Varela, the Agency Collection, Getty Images

Most people dream of retirement long before they get there. Perhaps you imagine spending hours on the golf course, taking a class on a subject that has always intrigued you or volunteering for your favorite cause. That's the idealized version of retirement.

Then there's reality.

Kiplinger's asked financial planners from the National Association of Personal Financial Advisors which retirement surprises their clients encounter most often. We also queried our Facebook community. Here are the five top financial surprises they came up with.

1. Health care costs

The cost of health care came up most often as a top retirement challenge among retirees on our Facebook page. According to Fidelity Investments, the average 65-year-old couple will spend about $400,000 out of pocket on health care throughout retirement until age 92, not including long-term-care costs.

Those new to Medicare may find it's more costly than they bargained for. While Part A of traditional Medicare, which covers hospital benefits, is free, you'll pay a premium for Part B to get coverage for outpatient services and a premium for Part D to get prescription-drug coverage. When the premium is added in for a private Medigap policy, which helps cover the costs that Medicare doesn't cover, a couple can end up paying $6,500 a year in Medicare premiums alone.

High-income beneficiaries get an extra shock: a premium surcharge. Even if your income isn't always high, you can land yourself in surcharge territory if you spike your income in one year with a Roth conversion, for example, or exercised stock options. The surcharge starts to kick in if your annual adjusted gross income (plus tax-exempt interest income) tops $85,000 if you are single or $170,000 if you are married and filing jointly.

Keep in mind that Medicare does not cover long-term-care costs -- an additional expense you must plan for.

2. Higher spending

You no longer have to budget for work clothes or commuting. But you may have to start paying for some things that you used to receive as perks through work, such as a company car, meals, travel or computers. "Small-business owners and professionals who retire are often surprised how many of their expenses were picked up by their company," says Bert Whitehead, the president of Cambridge Connection, in Franklin, Mich. "It is a jolt when they discover how much it adds up to."

Many retirees plan to see the world in their first few years of retirement, but traveling is pricey, and the costs of transportation, lodging and entertainment can add up quickly. Retirees' actual expenses "tend to be at least 10% to 20% higher than what had been budgeted," says certified financial planner Debra Morrison, of Trovena's Roseland, N.J., office. Even if you stay put, you'll have lots of free time to fill, and activities, such as golf or fixing up the house, cost money, too. "We tell clients that the 'common wisdom' that retirees spend 75% of what working people do is a dangerous thing to believe. We do goal setting to discover how they actually picture their retirement, and then try to place a price tag on it," says certified financial planner Barry Kaplan, of Cambridge Southern Financial Advisors, in Atlanta.

Those first few years in particular may be expensive as you enjoy your freedom from work, so budget accordingly when drawing up your retirement income plan. "Retirees desire to travel and become more active in the lives of their children and grandchildren," says certified financial planner Lazetta Rainey Braxton, of Financial Fountains in Chicago. "It's hard to plan for activities and 'unassigned gifting' when a retiree has never set aside these 'line items' in their budget."

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