The privilege of being called "Doctor" doesn't come easy. Doctors earn the title and more money because their education costs more and takes longer than most other professions.

Basic Requirements

Becoming a doctor -- whether a medical doctor (M.D.), Ph.D. (doctor of philosophy), Th.D. (doctor of theology) or J.D. (attorney) -- first requires an undergraduate degree, which typically takes three to four years to obtain. An entrance exam is required to be admitted to a graduate program. Finally, an exit exam or dissertation must be completed to prove you have the necessary skills and training to practice in your field.

Medical Education

To become an M.D. you must apply to medical school. If you beat the stiff competition for limited seats, based on your entrance exam, undergraduate performance and other factors, you will attend medical school for four years. Next, comes on-the-job training in a residency program for three to five years, depending on your field of practice. All physicians must then pass the U.S. Medical Licensing Exam to practice medicine in the U.S.

Cost

According to "U.S. News and World Report," the median in-state tuition for the 2009-10 school year at a public medical school was $22,800. Other doctorates, such as a Ph.D., pays one-fourth that amount. But, education is an investment in earning potential; typically the higher the cost in time and money, the greater and faster the payback in earnings.