This document describes the specific extraction, transformation, and load (ETL) process needed to support the “on-ramp” service for HIV data supplied by the ALPHA Network. This was the prototype use case for exploring the ETL functions at the Technical level. The OMOP CDM relies on agreed database table structures and standard vocabularies, and mapping data sources against these is a core feature of data sharing in the OHDSI framework. The integration of population data required some extensions of these vocabularies. This work is described here.