What does MD stand for? After a person's name, MD stands for Doctor of Medicine, the degree earned by graduating from medical school. The letters come from the Latin Medicinae Doctor, which is why the M comes first. When you see "Jane Lopez, MD" on a clinic door, it tells you she is a trained physician.
The same two letters have a second job on envelopes and forms. MD is the two-letter postal code for the state of Maryland. Context almost always settles which one is meant: a name in front points to the degree, while a city and ZIP code around it point to the state.
Quick facts
Stands for
Doctor of Medicine (Latin Medicinae Doctor)Also means
Maryland (postal code), managing director, muscular dystrophyType
Initialism, said "M D"Written as
MD or M.D., both acceptedUsed in
Name signatures, hospital badges, mailing addressesNot to be confused with
MA (Massachusetts), DO (osteopathic doctor), PhD
What does MD stand for in the medical field?
In medicine, the md full form is Doctor of Medicine. Here is how the letters map to the Latin phrase behind them:
| Letter | Latin | English |
|---|---|---|
| M | Medicinae | Of medicine |
| D | Doctor | Teacher, doctor |
In the United States, a person earns the MD after a bachelor's degree and four years of medical school. Most students take the MCAT to get in. The degree alone does not let someone treat patients on their own. A new MD then trains for several more years in a residency and must pass licensing exams and hold a state license.
What does MD stand for in medical terms on a chart?
Inside a hospital, MD usually still means the doctor. Staff may write "page the MD on call" or "MD notified." A few other medical uses exist, so read the whole note:
- Muscular dystrophy: a group of inherited conditions that weaken muscles over time. A chart might list "Dx: MD."
- Medical director: the doctor who oversees a clinic, nursing home or program.
- MDD: a longer code for major depressive disorder, not the same as MD.
Discharge sheet: "Follow up with your primary care MD in two weeks." Here MD simply means your regular doctor.
What does MD stand for in states and addresses?
On mail, MD is the postal code for Maryland. The older written short form is Md., with a period. You can read more on the Maryland abbreviation page.
Envelope line: "Annapolis, MD 21401." A state name between a city and a ZIP code tells you this MD is Maryland, not a doctor.
People often mix up the M codes. MA is Massachusetts, ME is Maine, MI is Michigan, MN is Minnesota, MO is Missouri, MS is Mississippi and MT is Montana. Only MD is Maryland.
Other places the MD abbreviation shows up
| Field | Stands for | Example |
|---|---|---|
| Business and banking | Managing director | "She was promoted to MD at the firm." |
| Mail and forms | Maryland | "Baltimore, MD" |
| Computing | Markdown file (.md) | "Edit the README.md file." |
| Music and media | MiniDisc | An older digital audio format |
In a work email from a bank, "the MD signed off" means a senior manager approved something. In an online code folder, a file ending in .md is a plain text file with simple formatting marks.
MD vs DO, PhD and other doctor titles
Both MD and DO doctors are fully licensed physicians in the US. DO stands for Doctor of Osteopathic Medicine. DO schools add training in hands-on treatment of muscles and bones, but both kinds of doctor can prescribe, do surgery and work in any specialty.
A PhD is a research doctorate in a subject like history or chemistry. A person with a PhD is called Dr. but is not a medical doctor. A JD is the law degree. For how to shorten the title itself, see the abbreviation for doctor.
Writing MD after a name
- Put a comma before it: "Sam Patel, MD."
- Do not use both Dr. and MD together. Write "Dr. Sam Patel" or "Sam Patel, MD," not "Dr. Sam Patel, MD."
- Periods are optional. M.D. looks more formal; MD is common on badges and websites.
- Pick "an" over "a," because M is pronounced "em": "an MD," "an MD program."
- The plural is MDs, with no apostrophe.
It is said letter by letter, "em dee," so it is an initialism. More degree letters live on the school acronyms page.
Questions people ask
Is an MD a real doctor?
Yes. An MD has finished medical school and, to practice, a residency and a state license. It is the most common degree held by physicians in the United States.
What does MD stand for after a name?
It stands for Doctor of Medicine. It shows the person earned a medical degree and is usually a practicing physician.
Is MD Maryland or Massachusetts?
MD is Maryland. Massachusetts uses MA, which is a frequent mix up on envelopes and forms.
Why is it MD and not DM?
The letters follow the Latin word order, Medicinae Doctor. English kept the Latin order even though we say Doctor of Medicine.
What is the difference between an MD and a DO?
Both are licensed physicians with similar training and the same rights to treat patients. DO programs add extra hands-on training in the muscles and bones.