What is the extent of responsibility for an employer to communicate employees' rights on the HSA at termination (or if the employer drops the HSA benefit program)?

There are no legal responsibilities to communicate employees rights when the HDHP is dropped or the employee terminates employment. The HSA is not a benefit plan, and therefore, not subject to ERISA/COBRA or any other post employment administration. However, from an employee relations perspective, many employers choose to explain that the HSA is an individually owned trust account, owned by the accountholder, that the employer will no longer be paying the monthly administration fees associated with the HSA, and when payroll deductions/employer contributions will end. If the employer is working with a UMB partner that has integrated web features, they may also want to let them know that they will receive information in the mail (i.e. debit card, instructions on how to access their account online) with new contact information and web functionality for UMB.