Use a comma between the name and the abbreviated degree, as in "Joe Smith, M.D." This also applies to professional titles; for example, "Mary Richards, director of development." If written in a sentence, include a second comma after the degree or title: "Joe Smith, M.D., will speak at the conference." Do not include the second comma if the name ends the sentence: "I plan on having lunch with Joe Smith, M.D."
If a person's name has Junior (Jr.), Senior (Sr.), II or another like term, it is not necessary to include any commas; for example, "Joe Smith Jr. is a very generous person." However, some people may follow older conventions and choose to write their name using commas: "Joe Smith, Jr." If you know this to be the case, it is appropriate to also write the name this way. In a sentence, set it off with commas the same way you would with a degree title: "We will know what Joe Smith, Sr., has decided any minute now."
When titles and degrees are used in the possessive form, do not include the second comma: "Joe Smith, M.D.'s speech was very moving."
Do not use a comma for titles that appear before the person's name, such as "the Reverend Joe Smith" or "Doctor Mary Richards." Also do not include both a person's title, such as doctor, and their corresponding degree, such as M.D., at the same time.