In most countries, the medical profession requires occupational licenses - only persons with a medical license bestowed either by a specified government-approved professional association or a government agency are authorized to practice medicine. Licenses are not granted automatically to all people with medical degrees. A medical school graduate must receive a license to practice medicine before he or she can be called a physician in a legal sense, a process that usually entails testing or examinations by a medical board. The medical license is the documentation of authority to practice medicine within a certain locality.
China issued the <<Law on Licensed Physician>> in 1995. The law required all newly graduated medical students to sit the National Medical Licensing Examination (NMLE) regulated by the National Medical Examination Center (NMEC) in order to be able to register with the local regulatory body. The law also requires that to be eligible to sit the exam, one student should have completed one years internship after obtaining his/her primary medical qualification (i.e. Bachelor of Medicine). The exam is a two part exam which includes a Clinical Skill (CS) test and a General Written (GW) test. The CS test consists of many stations, candidates must pass the CS test in order to sit for the GW test. The GW test consists of 4 units, candidates have 2.5 hours for each unit, running for 2 days. The CS is held in July, followed by GW in September each year.
The Instituto Colombiano para el Fomento de la Educación Superior (ICFES) and the Ministry of Education regulate the medical schools that are licensed to offer medical degrees. After completing all the schools' requirements to obtain a medical degree, physicians must serve the "obligatory social service" (in rural areas, research, public health or special populations e.g. orphan children) which usually lasts one year. After completing the social service, the "medical registration" may be obtained at the governor's office (Gobernación) of the Department (province/state) in which the obligatory term was served. This registration is homologous to a license in other countries and authorizes the physician to practice medicine in all the national territory. However, in order to practice in other departments, an inscription in that department must be performed. Unlike the US, there is no official licensing exam for medical graduates in Colombia, since this responsibility is delegated in medical schools upon receiving permission to confer medical degrees.
In India you have to write a screening test conducted by The Medical council of India in order to obtain a certification. They can practise medicine throughout the country after certifying themselves. It's optional to register towards their respective state medical councils.
The term "Medical License" is US-centric terminology. In the UK and in other commonwealth countries the analogous instrument is called registration; i.e. being on the register or being/getting struck off (the register). The General Medical Council is the regulatory body for doctor's licensing in the UK. Currently, there are two types of basic registration: "provisional registration" and "full registration", and two types of specialty registration: "specialist registration" and "GP registration". In November 2009, the GMC introduced the "licence to practise", and it is required by law that to practise medicine in the UK, all doctors need to be registered and hold a licence to practise. The registration information for all doctors holding or that have previously held a license in the UK is available online at the GMC website.
In the United States, medical licenses are usually granted by individual states. Only those with medical degrees from schools listed in the AVICENNA Directory for medicine or the FAIMER International Medical Education Directory are permitted to apply for medical licensure.
The federal government does not grant licenses. A physician practicing in a federal facility, federal prison, US Military, and/or an Indian Reservation may have a license from any state, not just the one they are residing in. The practice of "tele-medicine" has made it common for doctors to consult or interpret images and information from a distant location. Some states have special licensure for this.
The licensure process for most physicians takes between 3 to 6 months due to the extensive background checks, educational, training, and historical primary source verifications which are required.
Beyond the more general criticisms of occupational licensing that licensing increases costs and fails to improve quality, licensing in the medical profession specifically has been criticized as failing to enforce the standard practices they are charged with enforcing. In 1986, Inspector General at the US Health Department said that medical boards took "strikingly few disciplinary actions" for physician misconduct.  There have been a number of cases involving patient deaths where doctors only had their licenses removed years after multiple wrongful patient deaths had happened.  
Also, it has been said that because hospitals have had more legal burden placed on them in recent decades, they have more of an incentive to require their doctors to be competent. 
- "ECFMG 2009 Information Booklet - ECFMG Certification". Ecfmg.org. Retrieved 2008-11-08.[dead link]