Microlensing offers a unique way to constrain the physical extent of different emission regions in a lensed quasar, putting to test various accretion disk and continuum emission models. I discuss recent results from our dual-band Bayesian Monte Carlo analysis of microlensing in the system SBS 0909+523, where we marginally detect a shallower temperature slope than predicted by standard accretion disk models. The expansion of our monitoring program into the NIR, coupled with ongoing Chandra monitoring programs, will provide broad-spectrum constraints on the structure of quasar continuum emission regions. I conclude by discussing how a joint microlensing analysis in the optical and X-rays provides robust constraints on the extent of the X-ray continuum emission region and the accretion disk radius, disfavoring models involving an extended X-ray corona.