A stethoscope surrounding a roll of bills.

You do everything you think you're supposed to. You maintain good health insurance. You choose in-network doctors and hospitals. You pay the bills you think you owe.

But despite your best efforts, you could still wind up having problems with a medical bill that could affect your credit standing.

Nearly 3 in 10 insured Americans had an unpaid medical debt sent to a collection agency, according to a recent nationally representative Consumer Reports survey of 1,000 adults who had a medical expense over $500 in the last two years. 

Of those, 24 percent didn't realize the bill was owed and 13 percent said they never received the bill in the first place. Another 10 percent said the bill was sent to collections mistakenly, even though they had already paid it.

Of course, sometimes a medical bill goes unpaid because you don't have the money. Other bills become delinquent because of billing errors or an insurance dispute, which can take months to untangle. (Find out more about how to dispute a medical bill here.)

But whatever the situation, the impact is the same. Medical bills, like any unpaid debt, can do major damage to your finances if left unresolved.

The delinquent bill will eventually show up on your credit report and drag down your credit score. A low credit score can make it more expensive to borrow or could result in a loan being denied. Employers and landlords often look at your credit history, too. 

Nearly one-fifth of Americans say their credit score has been negatively affected by unpaid healthcare bills, according to our survey. 

More on managing medical bills

There is some good news, though. Medical debt is treated somewhat differently from other unpaid accounts, like credit cards or student loans.

Unlike traditional lenders, your doctor or hospital typically doesn't report unpaid bills to a credit reporting agency. Healthcare providers usually send the unpaid bill to a debt collector, which in turn reports it. So it may take more time for an unpaid medical bill to show up on your credit report and hurt your credit score.

There are also new regulations aimed at giving people more time to resolve problems with healthcare bills or come up with a payment plan before it can have an impact on your credit standing.

When it comes to dealing with medical bills, "consumers have more rights than they realize," says Jenifer Bosco, a staff attorney at the National Consumer Law Center who specializes in medical-debt issues.

If you're struggling to pay a medical debt or resolve a problem with a healthcare bill, here's how to minimize the impact on your finances. 

What to Do

Know your rights. New regulations that kicked in last September make it harder for medical debt to hurt your credit score. The three major credit reporting agencies—TransUnion, Experian, and Equifax—have to wait 180 days before putting an unpaid medical bill on your credit report.

The change gives you more time to navigate what is often a lengthy dispute process if you have a problem with your insurance coverage or you think a healthcare provider charged you incorrectly.

If you are disputing a coverage denial with your insurer, contact the healthcare provider to let it know and ask for more time before it sends your unpaid bill to a debt collector, says AnnMarie Quintaglie McIlwain, CEO of Patient Advocators, a service that helps people with medical billing and insurance problems.

"It'll be much harder to deal with the bill once it is turned over to a collection agency," says McIlwain.

Also new: Unpaid medical bills that later get paid by your insurer must be removed from your credit report so they don't continue to damage your credit score. Monitor your credit reports, and if the bad debt doesn't disappear, write to the credit reporting agencies to request that the debt be erased and provide proof of payment by the insurer, advises McIlwain.

Depending on the state where you live, you may have additional protections, says Bosco from the National Consumer Law Center.

For example, in California and Massachusetts, if you appeal an insurance denial for a medically necessary procedure, your bill can't be sent to collections while the appeal is going on. A few states, such as West Virginia and North Carolina, ban wages being garnished for medical-debt collections.

Others states have laws that prevent liens being placed on your home if you have unpaid medical debt. Check with the attorney general in your state to find out how it works where you live. 

Understand the risks. If you don't resolve the debt, your healthcare provider can turn the bill over to an outside debt collection agency and your unpaid bill will eventually show up on your credit report. That will drag down your credit score, which is used to predict the likelihood that you won't pay your bills.

Having a low credit score can have an impact on a wide number of financial transactions, such as applying for a mortgage, getting a new credit card, or buying a car. Landlords and employers often ask for permission to run a credit check on you.

How much an unpaid medical bill affects your credit can also depend on which credit-scoring model is used by the organization checking your credit. There's some good news here, too.

Most lenders use FICO scores, which are determined by an algorithm that is updated periodically. Under the newest FICO rating, FICO Score 9, medical debt is weighted less than other liabilities. But the most commonly used version is still FICO Score 8, which treats all debt equally. So if you're applying for a loan, find out which score the lender uses.

If you never pay the debt, delinquent accounts can take up to seven years to drop off your record, though the impact on your credit score decreases over time.

Make a deal. If the bill is legitimately owed but paying it would be a struggle, try to negotiate with the healthcare provider to lower the amount or write it off. Nearly 40 percent of people in our Consumer Reports survey negotiated payment and 57 percent of them were successful in lowering their bill. The tab may be reduced if you pay the whole amount up front.

Don't put the debt on your credit card. You will be charged high interest, and it will look like regular debt to creditors, so any protections associated with medical bills won't apply. Another option is to ask your medical provider for a payment plan. Many offer installment payment options with little or no interest.

See whether you qualify for a hospital's financial assistance or charity care programs. Nonprofit hospitals are required to devote a portion of revenue to charity care to qualify for the tax breaks that nonprofits get.