There are also medical clinics that offer medical services across the United States to those that qualify. Many medical studies and patents are publicly accessible on the web. There are organizations that offer compensation and health-care for those willing to volunteer for medical studies, questionnaires or clinal trials.
Additional lawyers and doctors offer “free” work that grow their business. Why do you think some lawyers offer free consolations. Why do some dental offices offer free cleanings or free consultations and exams when patients are looking for braces?
When folks equate “free” and “opensource” and mention “doctors” or “lawyers”, they imagine the lawyer working on their probate and wills for free or representing them on traffic accidents for “free” and in reality, that’s never going to happen.