There are multiple kinds of tests, all nasal swabs. Some have results in 1/2-1 hour, some in one day, or 2 days, or even longer. All require appointments, made days in advance. 

Rite Aid and Walgreens (with multiple locations) have testing. Some other pharmacies may as well. The pharmacies require filing out a form on internet, and are drive-up; you swab your own nose in your car. They do not require a referral or doctor's order. They do require either an insurance card or qualifying for the federal program for uninsured. 

Valley Immediate Care also requires an appointment, though not a doctor's order or referral. They also require insurance or qualifying for the federal program, or else the out-of-pocket cost is $132.34 for the test. 

LaClinica will do testing with an appointment at the Acute Care Clinic on Biddle in Medford, and you do not need to be a patient already. If you are uninsured or have no primary care provider, then you qualify for them to see you for testing. If you are uninsured, again there is the federal program or probably a sliding scale. 

Asante has drive up testing and in lab testing, with results in 1-2 days. They require anappointment and doctor's order or referral from your doctor, with insurance.  

There also may be low-cost home self-tests available at Walgreens and other pharmacies.