DEAR SAVVY SENIOR: Does Medicare cover 100 percent of all preventive health care screenings?

I’m due to get a colonoscopy and a few other tests, but I want to find out if I’ll have to pay anything before I proceed.

— New to Medicare

DEAR NEW: Medicare currently covers a wide array of free preventive and screening services to help you stay healthy, but not all services are completely covered. You also need to be aware that the repeal of the Affordable Care Act (aka Obamacare) — which helps financially support Medicare — may very well cause these free preventive services to be eliminated in the future.

But in the meantime, here’s how it works.

FREE PREVENTATIVE TREATMENT

Currently, most of Medicare’s preventive services are available to all Part B beneficiaries for free, with no copays or deductibles, as long as you meet basic eligibility standards.

Mammograms; colonoscopies; shots against flu, pneumonia, and hepatitis B; screenings for diabetes, depression, and heart conditions; and counseling to combat obesity, alcohol abuse, and smoking are just some of Medicare’s lengthy list of covered services.

But to get these services for free, you need to go to a doctor who accepts Medicare “on assignment,” which means he or she has agreed to accept the Medicare-approved rate as full payment.

Also, the tests are free only if they’re used at specified intervals. For example, prostate cancer PSA tests, once every 12 months for men over 50; or colonoscopy, once every 10 years, or every two years if you’re at high risk.

Medicare also offers a free “Welcome to Medicare” exam with your doctor in your first year, along with annual wellness visits thereafter. But don’t confuse these with full physical examinations. These are prevention-focused visits that provide only an overview of your health and medical risk factors and serve as a baseline for future care.

For a complete list of services along with their eligibility requirements, visit Medicare.gov and click on the “What Medicare Covers” tab at the top of the page, followed by “Preventive & screening services.”

HIDDEN COSTS

You also need to know that while the previously listed Medicare services are completely free, you can be charged for certain diagnostic services or additional tests or procedures related to the preventive service.

For example, if your doctor finds and removes a polyp during your preventive care colonoscopy screening, the removal of the polyp is considered diagnostic and you will likely be charged for it. Or, if during your annual wellness visit, your doctor needs to investigate or treat a new or existing problem, you will probably be charged here, too.

You may also have to pay a facility fee depending on where you receive the service. Certain hospitals, for example, will often charge separate facilities fees when you are receiving a preventive service. And, you can also be charged for a doctor’s visit if you meet with a physician before or after the service.

To eliminate billing surprises, talk to your doctor before any preventive service procedure to find out if you may be subject to a charge and what it would be.

COST-SHARING SERVICES

Medicare also offers several other preventive services that require some out-of-pocket cost sharing. With these tests, you’ll have to pay 20 percent of the cost of the service, after you’ve met your $183 Part B yearly deductible.

The services that fall under this category include glaucoma screenings, diabetes self-management training, barium enemas to detect colon cancer, and digital rectal exams to detect prostate cancer.

Jim Miller is a contributor to NBC-TV’s “Today” program and author of “The Savvy Senior.” Send your questions to Savvy Senior, P.O. Box 5443, Norman, OK 73070; or visit savvysenior.org.