CNN–Walmart, the largest retailer in the United States, will close all 51 of its health care clinics in six states and end virtual health care services, the company said Tuesday.

Walmart had made a big push into health care in recent years, opening clinics next to its superstores that offered primary and urgent care, labs, X-rays, behavioral health and dental work in six states — Arkansas, Florida, Georgia, Illinois, Missouri and Texas. Walmart had targeted rural and underserved areas that have a shortage of primary care facilities.

The announcement is an abrupt reversal in Walmart’s strategy and may leave a gap in health care access, particularly for lower-income patients without insurance who relied on the clinics. Walmart also said it will end virtual health care services.

Walmart said its health care push was not profitable for the company because of the “challenging reimbursement environment and escalating operating costs.”

“We determined there is not a sustainable business model for us to continue,” the company said.

Walmart said it will continue operating its 4,600 pharmacies and more than 3,000 optical centers around the country.

This is a developing story and will be updated.