Some of the largest HSA custodians by HSA assets are UnitedHealth Group Inc.’s Optum Bank, J.P. Morgan Chase & Co., HealthEquity Inc., Xerox Corp.’s BenefitWallet and HSA Bank, says Jon Robb, senior vice president for research and technology at Devenir Group LLC, an independent investment adviser and HSA consultant based in Minneapolis. Devenir’s HSASearch website has detailed information on almost 90 HSA custodians, including fee information.