Y dwarfs provide a unique opportunity to study free-floating, planetary-mass objects with atmospheric temperatures approaching those of known Jupiter-like exoplanets. Obtaining distances to these objects is an essential step in determining absolute physical parameters such as mass, age, and metallicity. Using Spitzer/IRAC ch2 images taken over baselines of ~2-5 years, we measure precise astrometric fits and distances for 21 late-T and early Y dwarfs. We also present Keck/NIRSPEC spectroscopy for eight new late-T dwarfs and one new Y dwarf discovery. With these data, we expand the sample of known objects that lie within ~20 pc of the Sun, allowing for a deeper understanding of the local field mass function at the coldest temperatures. Furthermore, the updated distances that we measure aid in better understanding the physical parameter space occupied by these ultracool dwarfs. Finally, we find that the Y dwarf class encompasses a large range in absolute magnitude in the near- to mid-infrared photometric bandpasses, indicating a broad range of physical properties, with varying gravities and metallicities.