Assisters provide in-person and phone-based support to help consumers narrow their plan options on the Affordable Care Act's health insurance Marketplaces. We elicited the perspectives of a national sample of thirty-two assisters from ten states on consumer plan selection and available Marketplace decision support tools (for example, total cost estimators and provider network look-up tools). Assisters identified several shortcomings that limited their use of decision support tools, such as nonspecific cost estimates and inaccurate provider network data. Assisters instead provided individualized cost estimates, called provider offices to verify network coverage, and found innovative strategies to help consumers access care affordably under their chosen plan. Two priorities emerged for optimizing consumers' Marketplace insurance selection process: improve the quality of data used in decision support tools and invest in assister programs. Assister strategies should be a benchmark for improving decision support tools, with lessons to be learned for future tool development.