In 2018, the US Geological Survey 3D Elevation Program (3DEP) began an effort to migrate all elevation products (point cloud/raster/vector) from legacy or proprietary formats to cloud-ready, open standard formats. We completed migration of all newly published products to open formats (LAZ, COG, Geopackage) in 2019, and will finish migrating existing products in 2020. This presentation will review the history of formats used by 3DEP (and formerly the National Elevation Dataset), the challenges of format migration for a national program with significant amounts of legacy data, and benefits achieved as a result of utilizing open data standards.