Those who operate illegal clinics in the United States typically fall into three main groups:
1. Individuals whose medical licenses have been revoked for various reasons.
2. Doctors from other countries practicing without a legal U.S. medical license, or those with green cards who are unable to practice medicine legally. Currently, the majority of individuals in this category are from China.
3. Those who failed within the fiercely competitive medical student system, or individuals like some veterinarians seeking to earn more money—so-called half-baked practitioners.
