Three major health insurance companies have agreed to publish their healthcare prices in a free online portal starting next year. The unprecedented move is designed to boost transparency in the U.S. healthcare system, notorious for its hard-to-access and seemingly random prices. Advocates hope public prices will lower healthcare costs over time as consumers make more informed choices in obtaining medical care and experts study pricing trends with greater ease. The nonprofit Health Care Cost Institute (HCCI) will create and administer the online portal in partnership with Aetna, Humana and UnitedHealthcare. Other insurers are expected to join the initiative soon, HCCI said.