DEERFIELD, Ill. — Walgreen Co. is testing a mobile app that enables patients to see a physician and obtain a prescription without leaving home.

The company said patients in California and Michigan can now contact a physician around the clock through Walgreens’ telemedicine app for smartphones or tablet computers.

The virtual visits cost $49, and doctors can diagnose and treat problems that aren’t emergencies and don’t require a physical exam.

Walgreens, which has more than 8,200 locations nationwide, plans to expand the service to additional states, although it did not say how long that might take.

The virtual doctor visit app, which was developed with MDLIVE and is available for both iOS and Android, does not require that patients fill prescriptions from those virtual visits at Walgreens pharmacies.

“Offering mobile and virtual access to board-certified doctors is a natural extension of the robust range of health services that Walgreens already offers,” said Dr. Harry Leider, chief medical officer at Walgreens. “We’re delighted to work with MDLIVE to provide our patients with a leading telehealth solution that will allow them to conveniently address their health conditions and needs with a medical ­professional.”

Last year Walgreens launched its Pharmacy Chat feature, which allows users to chat live 24/7 with members of its pharmacy staff, as part of its telehealth platform. The most recent announcement signifies an evolution and expansion of the platform by adding virtual doctor visits.

Company officials say that the availability of MDLIVE via the Walgreens mobile application further strengthens both organizations’ aim to bring quality health care that is convenient and affordable to everyone and that the initiative demonstrates Walgreens commitment to health care innovation and consumer engagement while introducing virtual health visit technology through MDLIVE.

“We are thrilled to work with Walgreens to offer consumers more choice for convenient, quality and cost-effective care,” said Randy Parker, chief executive officer of MDLIVE. “For the first time, a drug store’s website and mobile app users can share the convenience of accessing a board-certified doctor who can also e-prescribe medication when appropriate, via a secure, online video platform.”