Colonoscopies are one of the most common screening tests for colorectal cancer. As many as 19 million colonoscopies are performed every year in the United States.

The procedure not only allows your doctor to see the inside of the colon, but also allows them to biopsy any abnormal findings, like colon polyps, to see if they are cancerous.

Studies have shown colonoscopies to be 65% effective in preventing death from cancer on the right side of the colon and 75% from left-sided and rectal cancers.

Screening Colonoscopy

The goal of preventive medicine is to stop disease from happening whenever possible. It promotes healthy lifestyles and well-being for individuals and their communities.

In cases where disease does occur, the goal shifts to early detection. By identifying conditions early in their course, it becomes easier to treat them and to prevent any complications that could arise.

Screening tests are a key tenet of preventive medicine. They identify a condition that is prevalent in the population and provide a cost-effective way to screen for it when people are at risk.

Colon cancer is the fourth most common type of cancer in the United States and is the second most common cause of cancer death. A screening colonoscopy allows your doctor to check for cancer when you do not have symptoms.

If an abnormality like a colon polyp is detected, action can be taken to decrease the risk that it could progress to cancer. If cancer is detected, it prompts treatment to hopefully remove and decrease the spread of disease.

When the Affordable Care Act (ACA), aka Obamacare, was enacted in 2010, it made screening colonoscopies free for people on Medicare. That was the case, at least, if their doctor agreed to the Medicare fee schedule and was the one who ordered the test.

Diagnostic Colonoscopy

Unlike screening tests, diagnostic colonoscopies are performed when someone has signs and symptoms. This includes, but is not limited to, blood in the stool, a change in bowel habits, decreasing blood counts (with or without anemia), or unintentional weight loss.

Rather than screening a population, the focus of the procedure now lies on a concern for an underlying gastrointestinal condition in an individual. The goal is to diagnose that abnormality.

During a diagnostic colonoscopy, your doctor may do more than simply look at the colon. They may also take biopsies to find out if there are abnormal cells present that could represent cancer or a risk for cancer. They could even remove a polyp altogether.

Medicare will cover your diagnostic colonoscopy, but it will not be free. You will pay a 20% Part B coinsurance, and your Part B deductible also applies. This means you must first pay the full annual deductible that year ($203 in 2021). Medicare will then pay 80% toward the remaining costs.

Screening Colonoscopy Turned Diagnostic

Imagine you are scheduled for a screening colonoscopy. During the procedure, your doctor finds a polyp. They have one of two choices: biopsy or remove the polyp, or complete the colonoscopy without an intervention.

You will be hard-pressed to find anyone who will want to have a second colonoscopy to have a biopsy when it could have been done the first time around. Your doctor will ask you to sign paperwork before the screening to give permission for the biopsy if they find an abnormality.

Since it was scheduled as a screening test, you would expect the study to be free. Unfortunately, intervention with a biopsy changes the colonoscopy to a diagnostic procedure. Medicare will cover the test, but it will no longer be free. You will pay a 20% Part B coinsurance. In this case, however, the Part B deductible does not apply.

Frequency of Colonoscopy Screening

How often Medicare pays for screening depends on your risk. For people considered high risk, a screening colonoscopy can be performed every 24 months. To be clear, this is not based on the calendar year but on actual months. If your last colonoscopy was 23 months ago, Medicare will not cover it as a free screening test.

If this was not addressed in the ABN or if there was no ABN signed prior to the procedure, you are not liable to pay it. Keep in mind, ABNs apply only to Original Medicare, not to Medicare Advantage plans.

Medicare defines high risk as having one of the following conditions:

A personal history of adenomatous polyps A personal history of colorectal cancer A personal history of Crohn’s disease A personal history of ulcerative colitis A first-degree relative (sibling, parent, or child) who has had colorectal cancer or an adenomatous polyposis A family history of familial adenomatous polyposis A family history of hereditary nonpolyposis colorectal cancer (Lynch syndrome)

For people at low or average risk, screening is only covered every 120 months, or 48 months if their last colon cancer screening was by flexible sigmoidoscopy.

This does not mean Medicare won’t cover the test more frequently. If there is a medical reason for a colonoscopy, it may well be covered. You will be expected to pay the Part B coinsurance after paying down your annual deductible.

A Word From Verywell

As a screening tool for colorectal cancer, colonoscopies set the standard. They allow your doctor to visualize the colon and to take action if they see any abnormalities.

Medicare covers screening colonoscopy for free in most cases. However, if an abnormality is detected during a screening test, you could pay 20% of the cost if a biopsy or other intervention is done at the time of the now diagnostic colonoscopy.