Adam Kraus Title: The Demographics of Young Planetary Systems Abstract: Young and directly-imaged exoplanets offer critical tests of planet-formation models that can't be matched by RV surveys of mature stars. However, these targets have been extremely elusive to date, with no exoplanets younger than ~10-20 Myr and only a handful of direct-imaged exoplanets at all ages. I will present emerging results from three ongoing programs (in increasing order of optimism) that exploit a new technique, aperture-mask interferometry, to study the demographics and properties of young extrasolar planetary systems. First, based on a synthesis of disk and multiplicity surveys, I will establish what types of stars probably should not be expected to host extrasolar planets. I will then describe the discovery of several extremely low-mass companions in wide orbits around young stars; as I will discuss, these intriguing companions appear to be planetary in mass, but are more likely to form like stars or brown dwarfs than like bona fide "planets". Finally, I will present the first result from a new survey to directly search for young analogs to our own solar system (i.e. gas giants at 5-30 AU). While observing a young star with a known gap in its disk, our team discovered a young exoplanet embedded in the middle of that gap. Given the substantial mass of the circumstellar disk and the very red colors of the planet, I propose that the planet is actively accreting its gaseous envelope via a circumplanetary disk or shell, and thus that it has been caught at formation.