Dr. George Taler still makes house calls, driving his scuffed green Toyota sedan from one apartment to another, carrying a blue satchel with a laptop, hand sanitizer and a few medical tools. Inside each apartment, he practices medicine with old-fashioned care, spending half an hour with each patient. He takes out a stethoscope, a blood pressure cuff, a pulse oximeter. And if all goes well, when the visit ends, the patient ends up getting less—not more—medical care than if she'd shown up at a medical office.

Visit No. 4 on a recent morning was Maggie Barnes, an 82-year-old stroke patient with diabetes, high blood pressure and high cholesterol. She sat in a wheelchair and shared some easy banter with a doctor she’d been seeing for more than a decade. “I feel good!” Barnes said.