This document discusses collecting data on lesbian, gay, bisexual, transgender, and intersex (LGBTI) people to measure countries' progress toward achieving the UN's 2030 Agenda and leaving no one behind. It recommends developing an LGBTI Inclusion Index to measure opportunities and outcomes for LGBTI people across countries, noting current data gaps. The document calls for defining appropriate indicators for such an index and addressing challenges to begin systematically collecting this important data.