USCIS made the announcement on May 2, 2016 that they have completed data entry of all fiscal year 2017 cap-subject petitions in the computer-generated random process. USCIS has begun the process of returning unselected cases but due to the high volume of filings, USCIS is unable to provide a definite time frame for returning these petitions. USCIS asks petitioners not to inquire about the status of submitted cap-subject petitions until they receive a receipt notice or an unselected petition is returned. USCIS will issue an announcement once all the unselected petitions have been returned.

Source: USCIS