For the 2017 New York City Housing and Vacancy Survey (NYCHVS), the rent regulation coding sequence was adjusted to improve the accuracy of estimates of the rent stabilized housing stock. The 2017 NYCHVS methodology incorporates additional information on 62,000 units that registered with DHCR as permanently exempt. About 47,000 of these units were deregulated in 2011 or earlier, 9,000 units were deregulated between 2012 and 2014, and about 6,000 units were deregulated between 2015 and the 2017 NYCHVS survey period.