The Specialists Accreditation Board (SAB) determines the qualifications, experience and other conditions; as well as the training programmes which are to be recognised for registration as specialists under the Medical Registration Act. The duration of training for each specialty can be found on SAB website via the link:
http://www.healthprofessionals.gov.sg/content/hprof/sab/en/topnav/specialist_training/residency_training_programmes.html