Every year on his wedding anniversary Louis Sinclair pays a visit to his family physician for what has become a ritual: the annual physical.

“That way I don’t forget my anniversary and I don’t forget my physical,” says the 66-year-old in Raleigh, N.C., who has been getting regular checkups since he was about 40.

About a year and a half ago, the doctor diagnosed Mr. Sinclair with atrial fibrillation and sent him to a cardiologist. A CT-scan picked up a tumor on his lung that turned out to be cancerous. “I would have never known that if I hadn’t gone to my physical and followed up on this stuff,” says Mr. Sinclair, who owns a commercial real-estate company. He says the tumor was removed and he now seems to be fine.

Nearly two-thirds of U.S. adults say they get a physical exam every year, according to a 2014 Kaiser Family Foundation survey of 1,500 people. The federal Affordable Care Act requires insurers to cover annual physicals free of charge.

In the medical community, however, experts are divided on whether there is a benefit to getting an annual exam. Some research has shown regular physicals don’t reduce rates of illness or mortality and are a waste of health-care resources. They also could be harmful, for example, when false positives result in additional, unnecessary testing.

Other experts say a yearly checkup is an important part of building a physician-patient relationship and can lead to unexpected diagnoses such as of melanoma and depression.

“I think there are probably subsets of people who can go longer than a year between visits but I think it’s quite important for people to know their doctor before they get sick,” says David Himmelstein, a primary-care doctor in Bronx, N.Y., and co-author of an editorial published earlier in January in the journal Annals of Internal Medicine in support of annual checkups.

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