01/26/2015 02:12 pm ET Updated Mar 28, 2015

3 Health Expenses That Will Wreck Millennials' Finances (And What You Can Do About Them)

Sure, a visit to the doctor's office might be expensive, but don't bet on it being your largest health expense of the year - even if you're a young, healthy millennial. Taking an optimistic view of your future medical expenses might end up costing you more down the road.

"By definition, millennials think they are extremely invincible," says Dr. Dinesh Kumar, chief medical officer of HealthCare Partners. "They don't think they need health care."

As it turns out, many millennials struggle to cover basic health expenses. Over three in 10 millennials report having unpaid medical bills, according to a 2014 report by the Financial Industry Regulatory Authority. For these young people, unplanned medical expenses can be a huge burden on top of other financial obligations, such as student loans, rent and daily expenses. That's where planning ahead can make a difference.

Here are some health expenses for which millennials should prepare:

1. Recovering from an accident

Accidents happen every day - on the road, in the workplace, at home - and it's easy to get caught off guard by the medical expenses that follow.

"It's not unusual in this day and time to go to the ER for an hour and get a bill for $15,000," says Pat Palmer of Medical Billing Advocates of America. She adds that hospital stays are often even more expensive.

In addition to receiving large medical bills, you might also end up missing work because of your injuries, and that could eat even further into your finances.

What you can do: For surgical procedures, hospital stays or other major expenses, request itemized receipts from your health care provider. If you come across errors, such as duplicated charges (here's a list of more common errors), dispute them. Don't be afraid to appeal denied insurance claims, Palmer urges. If all that doesn't bring your costs down, consider hiring a medical billing advocate expert to get your medical costs down to a fair, affordable rate.

In the meantime, work on increasing your emergency fund. This will make it easier for you to cover basic living costs if you need to take unpaid time off work.

2. Developing a chronic disease

Millennials ages 18 to 29 run a higher risk of developing certain chronic diseases, Kumar says - and these conditions can come at a high cost. "It's a risk factor," he says. "Cancers occur in that age group. Lymphomas occur. Breast cancer can happen with familial predisposition to cancer in that age group."

Medical conditions such as these can easily derail a person's finances. Younger cancer patients, in particular, are two to five times more likely to declare bankruptcy than cancer patients over age 65, according to a 2013 study published in the journal Health Affairs. Chemotherapy and other associated treatments can take a big chunk out of your monthly budget.

What you can do: If you need ongoing care, try to get a plan that allows you to communicate with your doctor by email or phone for free so you can get the attention you need while saving time and money on copayments. If you're uninsured or have a high-deductible plan, compare prices for procedures at different hospitals to make sure you're getting the best deal and look for online resources to minimize the cost of prescription drugs.

Consider setting up a flexible spending account (FSA) through your employer or a health savings account (HSA) on your own if you expect a lot of out-of-pocket health expenses. Using these pre-tax dollars can help you trim your medical costs.

3. Losing your job-based health insurance

Whether you get laid off or decide to search for a new job, there may be a time in your 20's or early 30's when you lose your job-based health benefits. If this happens and you can't immediately enroll in your new workplace's health insurance plan, you'll have to decide how you want to cover your medical expenses.

What you can do: If you lose your job-based coverage, you can request a continuation of coverage through the Consolidated Omnibus Budget Reconciliation Act, buy a health care plan on or pay a penalty and remain uninsured.

Before opting for a high-deductible plan, weigh your options. Can you afford a lower-deductible plan? Consider making the change. If not, be prepared to negotiate your medical bills so you won't end up with charges you can't afford.

If you're uninsured, "always ask for the uninsured discount," Palmer says. The uninsured discount typically ranges from 35% to 50%, she notes, and is often available to people who have high-deductible plans, as well.

"You're fortunate if you're healthy and you don't have to use the health care system," she says. "But the more you can educate yourself about the industry, the more money you'll save."

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