The 2-1-1 information and referral helpline connects economically vulnerable Americans with needed health and social services in their communities. This longitudinal study followed a random sample of 2-1-1 callers in Missouri (n=1,235) to determine the results of the referrals they received. One month after calling 2-1-1, most remembered receiving (93%), tried contacting (91%) and reached (82%) at least one referral they received. Far fewer (36%) received assistance from the referral, ranging from 17% for housing assistance to 67% for food assistance. Callers receiving assistance were much more likely than those not receiving assistance to report at 1-month follow-up that their problem had been resolved (OR=3.0, 95% CI=2.2, 4.1), although this was less true among callers with multiple unmet basic needs. Findings explain how 2-1-1 helps callers resolve problems, but also identifies missed opportunities in the current system. Future research could elucidate how 2-1-1 callers resolve problems and find ways to improve outcomes for the most disadvantaged 2-1-1 callers.