This document compares three options for handling an organization's HR function: doing it in-house, using multiple vendors, or outsourcing to a single vendor HR outsourcing provider. Doing HR in-house takes significant time away from core business activities but keeps costs low. Using multiple vendors shifts some tasks to experts but requires managing many relationships. Outsourcing to a single vendor HR provider through a PEO simplifies administration, improves efficiencies, and allows a focus on core competencies, while the provider handles back-office functions and strategic HR services.