A yearly physical is the standard preventive measure for adults, but many Gen Z patients are forgoing regular doctor appointments.

More than 1 in 4 young adults don’t have a primary care provider, according to a recent national survey by the Ohio State University Wexner Medical Center.

For Gen Zers who do have a physician, most skip scheduled checkups or don’t schedule them: Only 47% of 18- to 29-year-olds said they have had an annual wellness visit in the past year, according to the survey findings, released June 29.

Skipping doctor visits in early adulthood could have severe consequences, experts say, noting that missed prevention opportunities earlier in life can lead to greater chances of developing later-in-life diseases and conditions. In recent years, colorectal cancer rates have skyrocketed in younger adults, becoming the leading cause of cancer deaths for people younger than 50.

“An annual visit isn’t just about today’s health — it helps identify future risks, keeps preventive care on schedule and gives you a trusted clinician who knows your medical history and can help navigate health concerns, be they physical health or mental health concerns, as they arise,” said CNN wellness contributor Dr. Leana Wen, an emergency physician and clinical associate professor at George Washington University, in an email to CNN. Wen was not involved in the study.