Shares of health insurance companies fell on Wednesday UnitedHealth Group warned of higher medical expenses like older Americans start catching up on operations they delayed during the Covid-19 pandemic.

Shares of UnitedHealth, the largest U.S. health care provider by market value, closed about 6% lower. Insurance company focused on health care Humana fell by 11%.

Elevation Health closed roughly 7% lower and CVS Healthwhich owns insurer Aetna, fell nearly 8%.

In recent years, insurance companies have benefited from delays in non-urgent procedures due to lack of staff in the hospital and the pandemic that saw hospitals flooded with Covid patients. Hospitals at the time were widely considered too risky to enter into elective procedures.

But on Tuesday, UnitedHealth executives indicated that the trend may be reversing.

The company saw “strong ambulatory care” during April, May and early June, Chief Financial Officer John Rex said at the Goldman Sachs Healthcare Conference.

Most of the increase in care comes from Medicare enrollees receiving heart procedures and hip and knee replacements at outpatient clinics, Rex says.

UnitedHealth CEO Timothy Noel said older adults covered by Medicare have “more convenient access to services for things that they may have put off a little bit.”

Rex said the amount of premium income spent on care for the second quarter may be at a high level or “slightly above” expectations due to an increase in procedures.

Actions by manufacturers of medical devices Medtronic and Stryker they jumped 2.5% and 4% after the UnitedHealth notes.

Actions by hospital operators HCA Healthcare and Tenet Healthcare also elevated above.