Andy Boden (Caltech) Title: Young Stellar Systems at High Angular Resolution with Infrared Interferometry Abstract: The Pre-Main Sequence (PMS) is among the evolution states where our knowledge of stellar physics is the most uncertain. For the past decade PMS stars have been a particularly fertile area for study with Long-Baseline Infrared Interferometry. The interferometric study of both the circumstellar environments of young stars, and multiple PMS systems is fundamentally changing our view of how these systems form and evolve. In this talk I will review the past contributions made by NIR interferometry, and areas where I believe more contributions are forthcoming.