Is there a minimum amount that employees must contribute? Admin September 06, 2018 19:31 Updated No. There is no minimum contribution amount required of either the employee or the employer. Related articles An employee reaches the age of 55. Is the extra contribution allowed at the beginning of the tax year, not just after the employee turns 55? Where can I find the Coordination of Benefits (COB) letter? I am completing Part 3 of the 1095-B per IRS Instructions. What is the correct Part 3 response for our agency? Do agencies have to offer the HSA through payroll or can employees contribute post-tax? If employees don't want to contribute to their HSA through payroll deduction, how can they contribute?