Carol Y. Vliet’s cancer returned with a fury last summer, the tumors metastasizing to her brain, liver, kidneys and throat.

As she began a punishing regimen of chemotherapy and radiation, Mrs. Vliet found a measure of comfort in her monthly appointments with her primary care physician, Dr. Saed J. Sahouri, who had been monitoring her health for nearly two years.

She was devastated, therefore, when Dr. Sahouri informed her a few months later that he could no longer see her because, like a growing number of doctors, he had stopped taking patients with Medicaid.

Dr. Sahouri said that his reimbursements from Medicaid were so low — often no more than $25 per office visit — that he was losing money every time a patient walked in his exam room.