Specialist doctors focus on a particular field of medicine such as cardiology or urology. All specialist doctors have many years of education and training in their chosen fields. Medical specialties are generally lucrative career choices. According to Salary.com, as of November 2009 the median salary for a cardiologist is more than $295,000 per year; the median salary for a urologist is more than $303,000.

Earn a pre-med undergraduate degree, which takes about four years. An appropriate undergraduate course of study includes biology, chemistry, physics, mathematics and English. Your student adviser will recommend the courses you should take.

Take the Medical College Admission Test (MCAT). MCAT scores are required with your application for admission to most medical schools.

Earn a graduate degree from an accredited medical school, which takes another four years. Medical school curricula include classroom study, lab work and clinical rotations during which you receive hands-on experience treating patients in various fields of medicine. Clinical rotations include emergency medicine, pediatrics, obstetrics and gynecology, surgery and psychiatry.

Complete a residency program in your selected specialty. The length of the residency program depends on the specialty you choose, but according to the American Board of Medical Specialties (ABMS) it usually takes three to five years. The first year of residency is sometimes referred to as an internship. Medical students apply for residency programs before graduating from medical school; space is limited and programs are competitive.

Take the United States Medical Licensing Examination (USMLE) to become licensed to practice medicine. Apply through the state medical board in the state in which you wish to become licensed.

Become certified in the specialty of your choice by a member board of the American Board of Medical Specialties. The ABMS consists of 24 member boards, representing specialties such as emergency medicine, neurological surgery, obstetrics and gynecology, medical genetics and anesthesiology. You must pass an exam to become board certified.