This publication provides guidance on the public health response to pretreatment HIV drug resistance (HIVDR) to non-nucleoside reverse-transcriptase inhibitors (NNRTIs) among people without prior antiretroviral (ARV) drug exposure or people with prior ARV exposure who are initiating or reinitiating first-line antiretroviral therapy (ART). It also provides the consensus prevalence or threshold of pretreatment HIVDR to NNRTIs at which specific public health actions are triggered. This publication is a supplement to Chapter 4 of the 2016 WHO consolidated guidelines on the use of antiretroviral drugs for treating and preventing HIV infection (2016 WHO consolidated ARV guidelines).