Box 6 includes to Corporations:

Enter payments of $600 or more made in the course of your trade or business to each physician or other supplier or provider of medical or health care services. Include payments made by medical and health care insurers under health, accident, and sickness insurance programs. If payment is made to a corporation, list the corporation as the recipient rather than the individual providing the services. Payments to persons providing health care services often include charges for injections, drugs, dentures, and similar items. In these cases, the entire payment is subject to information reporting. You are not required to report payments to pharmacies for prescription drugs.

The exemption from issuing Form 1099-MISC to a corporation does not apply to payments for medical or health care services provided by corporations, including professional corporations. However, you are not required to report payments made to a tax-exempt hospital or extended care facility or to a hospital or extended care facility owned and operated by the United States (or its possessions), a state, the District of Columbia, or any of their political subdivisions, agencies, or instrumentalities.