"Doctor" is an honorific. If you're addressing him personally, "Dr. Smith" is better; if you're writing it somewhere, it's fine (and may in some cases be preferred) to add the specific degree(s) and societies: "Dr. Fred Smith, MD, FACS." Particularly in lists this is useful, as it may help distinguish Fred Smith the surgeon from Fred Smith the dentist.
Either is correct , unless of course the doctor has a Phd.
The correct usage would be "Dr. Robert Roberts" or "Dr. Robert Roberts, MD." The combination of "Dr." and "MD" is redundant because they both signify a medical doctor.
Walter J. Smith, Jr., MD. Never use Dr and MD (or PhD) in the same name.
Mr. John M. Smith and Dr. Mary F. Smith is correct, or John M. and Mary F. Smith, or Mr. & Mrs. John M. Smith. One should never become awkward in usage for the purpose of being politically correct. It simply draws people's attention unnecessarily.
If you were sending a letter to John Smith, MD - you could address the letter to Dr. Smith.
Dr. Horace smith,md
It is generally acceptable to use "Dr." before a person's name if they hold multiple degrees, such as MD and Ph.D. However, it is also common to choose only one title to use based on the context or preference of the individual. In formal situations, both titles can be used together.
A. Dear Dr. Smith, M.D.:
I have never seen Dr after a name. It may be MD, PhD, EdD, DDS, etc. depending on your field of study. Still, if the degree is a doctorate, the Dr would go before the name. Thus as an example, John Smith PhD, or Dr. John Smith.
First, you do not use both. Typically, when work related the abbreviation follows the name. For example, John Williams MD. Or John Williams PhD.
you can contact him here http://www.healthgrades.com/directory_search/physician/profiles/dr-md-reports/Dr-Keith-Louwenaar-MD-686B880C.cfm and find out
Dr. Amy Castillo is a pediatrician who practices in Kensington, MD.