Americans on average spend more on health care than they do on groceries, according to the Bureau of Labor Statistics’ latest Consumer Expenditure Survey. Saving money on medical care is a lot tougher than saving money on food, however. Two big culprits: opaque pricing and ever-changing insurance company rules about what’s covered and what’s not.

For help in cutting costs, I turned to a uniquely qualified individual: Carolyn McClanahan, an emergency room doctor turned certified financial planner. McClanahan, director of financial planning at Life Planning Partners in Jacksonville, Florida, frequently speaks at industry conferences, teaching other advisers how to help their clients best navigate the health care system.

These are the three questions she suggests everyone ask:

How do I use health care?

McClanahan divides people into low, medium and high health care users. Low users are generally in good health and rarely go to the doctor. High users tend to have chronic health conditions or young children and visit the doctor several times a year. Both can be good fits for high-deductible health care insurance, McClanahan says.

People who spend a lot on health care will quickly meet a high deductible and often end up spending less overall on high-deductible plans, which have lower premiums.

Conversely, people who use very little health care may also spend less on a low-premium, high-deductible plan. It’s people in the middle — who do visit the doctor, but likely won’t spend enough to meet a high deductible — who should consider lower-deductible plans, she says.

One caveat: People who have a high-deductible plan should have enough savings to cover that deductible. The downside of such plans is that they may discourage people from seeking the care they need. Earmarking cash to cover the deductible can help thwart that tendency. If that’s not possible, a low-deductible plan may be better for someone’s health.

Also, routine services that can detect or prevent illness — such as vaccinations and certain cancer screenings — are free in many health insurance plans, regardless of the deductible.

Are you covered in my network?

This is a much better question to ask a provider than “Do you take my insurance?” An out-of-network provider may be willing to bill your insurer but can wind up costing you much more than an in-network provider. Also, insurance companies offer many different plans, and doctors that are in an insurer’s preferred provider organization may not be in its high-deductible health plan network.

People should ask, “Is this in network?” for every aspect of their health care, from the laboratory that tests their blood to the anesthesiologist who’s scheduled for their surgery. Keep a written record of whom you talked to and when, McClanahan recommends. This can give you ammunition to get bills covered or discounted if the information you were given is wrong.

For prescription medications, ask your insurer, “How is this covered?” Insurers have formularies with different copays for different drugs, and some may not be covered. Patients can ask their pharmacists if there is a less expensive version available, such as a generic.

For some drugs, paying cash is cheaper than an insurance company’s copay. A 30-day supply of metformin, a drug to treat high blood sugar, may have a $10 copay but be available for $4 cash at Walmart WMT, +0.30% and other outlets.

You also can look for coupons and other discounts at GoodRx.com. Another way to save: Regularly ask your doctor to review the medications you’re taking to see if you can stop or swap any for a less expensive version.

“Doctors are too quick to throw a pill at you,” McClanahan says. “Ask, ask, ask, and shop around.”

What else can I do?

Sometimes, medications or surgery are less effective than alternative treatments. Treating lower back pain with exercise, cognitive behavior therapy and focused breathing is more effective than the treatments doctors usually prescribe, including rest, surgery and injections, according to articles in the British medical journal The Lancet in March.

Doctors may not suggest lifestyle changes because they believe most patients won’t make the effort, McClanahan says. But losing weight, exercising and quitting tobacco can lessen symptoms or prevent many diseases. Those with prediabetes, for example, can often avoid developing Type 2 diabetes with changes in diet and exercise.

“If the doctors aren’t able to provide that education, ask if they will refer you to someone who will, a nutritionist or physical therapist,” she says.

Not all doctors welcome empowered patients who ask questions, McClanahan notes. If yours doesn’t, she recommends finding one who is more collaborative.

“Doctors are not gods. They should work with you,” she says.