I present full-polarization VLBA images of 1665 and 1667 MHz hydroxyl (OH) masers in massive star-forming regions. Magnetic fields deduced from Zeeman splitting suggest organized field structures with at most one line-of-sight field direction reversal in each source, suggesting that the magnetic field is not highly twisted by the process of star formation. Correlations between magnetic field directions around star-forming regions separated by kiloparsecs have implications for the Galactic magnetic field. The clustering and ages of OH masers are consistent with the location of OH masers in the ionization-shock front zone around a central ultracompact H II region. I discuss the significance of linear polarization as well as possible complications arising from Faraday rotation.