"The physician knows the diagnosis; the pharmacist knows the drugs," Boyd says simply.

Do your research

Most people would rather do their taxes than read their health care insurance plan, Pollitz says. "It's just icky. I think that's the technical term."

But understanding your plan -- such as knowing your deductible or any co-pays for which you're responsible -- will help you prepare for upcoming expenses.

Some larger companies offer benefits counselors who can help guide you through the fine print, Pollitz says. If one is not available, HealthCare.gov offers definitions of basic terms, compares your options (HSA or FSA? PPO or HMO?) and explains the rights/protections given to you under the Affordable Care Act.

There are also several websites that can help you lower your health care costs by letting you know what you should be paying.

Searching for Medicaid or Medicare options, or the right individual health insurance plan? HealthPocket.com rates insurance companies based on government, nonprofit and commercial data sources to show you all your options.

Rice's Healthcare Blue Book basically offers blue book prices for medical procedures -- like the "Kelly Blue Book" value for a car that you go into the dealership with to negotiate.

Type your ZIP code into HealthcareBlueBook.com and select the medical procedure or test you need. The site will then return the "fair" price for that test in your area.

GoodRx.com offers a similar service for prescription medications. Consumer Reports picked it as the best app for finding the lowest drug prices in store and online. The site also shows generic alternatives (if there are any) and posts coupons to help you save.

Fight back

If in the end, your bill still ends up being more than you expected to pay, don't be afraid to fight back, Pollitz says.

"People are inclined to take 'No' for an answer," she says. "You can always complain. You can always appeal."

Through the ACA, states are starting Consumer Assistance Programs that are designed to empower patients. One of the jobs they're required to do is help you file an insurance claim, Pollitz says.

If the insurance company denies the appeal (which they usually do, Pollitz says), you have the right to take it to an outside reviewer. Those who do, Pollitz says, win about half the time.

Visit HealthCare.gov or your state's labor department for more.