Disclosed are devices and methods related to autotransformer-based impedance matching for radio-frequency (RF) applications. In some embodiments, an impedance matching device can include a primary metal trace and a secondary metal trace, each having a respective number of turns. Such metal traces can be interconnected to form an autotransformer with the primary metal trace and the secondary metal trace being in respective planes separated by a selected distance. Such an autotransformer can be utilized to, for example, facilitate impedance matching of an amplified RF signal from a power amplifier (PA). In some embodiments, the impedance matching device can be implemented as an integrated passive device (IPD) mountable on a packaging substrate. Such an IPD can be configured to allow stacking of another component on the IPD to yield a number of desirable features in products such as RF modules.