If you know a doctor socially, either as a colleague, friend or family member, you might seldom call him "Doctor" during conversation. However, addressing a letter to this person is a different story. Regardless of your reason for writing, you must follow the proper rules of etiquette to ensure you address the doctor correctly on the envelope and in the letter itself.
Write the doctor's first and last name on the top line of the address portion of your letter's envelope, followed by a comma.
Include "MD" after the comma on the first line. For example, if your doctor's name is Stephen Williams, your first line should read, "Stephen Williams, MD." Note that it's redundant to include "Dr." and "MD" on either end of the doctor's name. For someone who holds a doctorate, address your letter's envelope with "Dr." and the person's first and last names. It's not necessary to use this designation if the person doesn't refer to herself as "Dr."
Add the doctor's mailing address on the next line of the letter. For example, write, "123 Main St., Anywhere, CA, 09512." In the event you've chosen to write to the doctor at work, write the name of the doctor's clinic or hospital on the second line of the letter. For example, write, "Western Regional Hospital." Write the mailing address on the next line.
Write "Dear Dr." and the doctor's last name on the top line of the letter itself. For example, begin your message with, "Dear Dr. Williams." Use this prefix for those with doctorates, too, unless the person has specifically told you to avoid doing so.
- Michael Gann/Demand Media