When are you going to retire, Doc? It’s a question I was asked several times a week. When it didn’t elicit a satisfactory answer, I would receive a variation on the same theme the next visit: How long are you going to do that commute? My patients knew that we had sold our house and moved to a condo closer to the city, which led to a 45-minute drive to and from my suburban office each day.

I was in my late 60s and had been a family doctor in the same town for nearly 40 years. I had taken care of several generations within the same families. For the past nine years, a partner and I had run a concierge practice, where an annual $1,600 membership fee covered all our care. Our only concern was the patient’s welfare, not an insurance company’s; we provided same day in-office care and home visits, and there was no time pressure when seeing a patient. It was a wonderful way to practice medicine.

But in 2016, my 72-year-old partner wanted to retire. His decision made me reconsider my own desires. I concluded I didn’t want to be in practice by myself; it was time for me to go, too. After a long search, we found someone we trusted with our patients’ care to buy the practice.

The median age for retirement from clinical activity for primary care physicians is 65, according to a report from the American Academy of Family Physicians. The number of physicians over 65 who are actively practicing medicine quadrupled from 1975 to 2013. In 2016, the Federation of State Medical Boards’ census reported that the number of actively licensed physicians 70 and older numbered 94,969. I’m part of that club.

The reality is: As your longtime doctor ages, there may come a point when you start to wonder whether your doctor is still competent and up to date on the best practices or whether it’s time to end what is likely a trusted relationship and go find someone new.

It’s a valid concern.

Hospitals have wrestled with this problem for many years. On the one hand, aging doctors are often part of the hospital’s leadership. On the other hand, hospitals have a duty to keep their patients safe. In recent years, some hospital systems have introduced mandatory testing (of cognition, health, strength, motor skills, balance and reaction time) for doctors over 70.

It’s harder to spot loss of competence in private practitioners who have few or no affiliations with hospitals or peers who could potentially notice worrisome changes. The hospital testing has not been scientifically validated through good studies and, in any case, it is hard to assess physician competence.

I know a doctor, now in his 70s, who has recent memory loss — he can no longer do his billing — but his distant memory is intact. By all accounts, he remains a competent doctor and still sees patients, receives referrals and gives lectures. He enjoys practicing and isn’t ready to stop. There is no mechanism to get him to quit.

I have seen several colleagues restrict their practices as they get older. They no longer do complex or long procedures or they stop operating altogether because they no longer have the stamina or they feel like they are not as skilled as they used to be. They work fewer hours, thus reducing their stress level. These measures may allow them to work comfortably for several additional years.

Denial is a huge factor for all of us when it comes to recognizing cognitive decline. Doctors are no different in this respect, especially considering that being a physician is an identity and often a calling, not just a job and a way to earn a livelihood.

I’ve had friends and patients ask me how they can assess whether their aging physician should stop practicing medicine or whether they should stop going to that doctor. Here are some red flags I tell them to watch for:

●A doctor you’ve known for many years doesn’t remember you or frequently mixes you up with someone else.

●The physician is dismissive or impatient — and this is a change in his or her usual demeanor.

●When you ask your doctor a question, you often get a confusing or convoluted answer and asking follow-up questions doesn’t help clarify the matter.

●The physician repeatedly forgets to do things (whether it’s order tests, research a question or condition you have, refer you to a specialist, call you with test results or complete another task) that he or she promised to do.

●Your physician seems to refer you to another medical professional for nearly every ailment.

● ●Your doctor has difficulty hearing (or seeing) or seems to be a bit shaky handling instruments.

Ultimately, it’s important to follow your gut. If you don’t feel comfortable or confident in your doctor, find a new one, regardless of how old or young your current doctor is. It really should be that simple.

I am now 70 years old and I work part time in a walk-in medical clinic. I love being a doctor and I love the work it involves. My mind is sharp and I’m in good health — and my hope is that my age has allowed me to acquire greater wisdom, compassion, resilience and stress tolerance.

My own doctor is over 65 and he still appears on the local “Best Doctors” lists — because he has good judgment, a deep reservoir of knowledge, a great bedside manner and other qualities that make him a wonderful doctor. My feeling is: That’s what everyone should look for in a physician of any age.

Jonathan Maltz is a family physician practicing part time in Bethesda, Md. For 40 years, he practiced full time in Olney, Md.