Employers may first apply for 2016 H-1B visas for individuals not currently in H-1B status on April 1, 2015 with a start date of October 1, 2015. USCIS received approximately 172,500 H-1B petitions during the first week applications were accepted for the 2015 H-1B visa cap and conducted a random lottery to select the 85,000 petitions for the H-1B cap (65,000 for the general category and 20,000 for the US advanced degree category). We anticipate similar high demand again this year. This H-1B cap limitation does not apply to extensions of H-1B status or those obtaining H-1B status to teach at colleges, universities, related nonprofit or government research organizations or J waiver physicians.
http://www.natlawreview.com/article/employers-april-1-start-date-2016-h-1b-visa-applications