Health Savings Accounts (HSAs)
A health savings account (HSA) is a tax-exempt trust or custodial account you set up with a qualified HSA trustee to pay or reimburse certain medical expenses you incur. You must be an eligible individual to qualify for an HSA.
No permission or authorization from the IRS is necessary to establish an HSA. You set up an HSA with a trustee. A qualified HSA trustee can be a bank, an insurance company, or anyone already approved by the IRS to be a trustee of individual retirement arrangements (IRAs) or Archer MSAs. The HSA can be established through a trustee that is different from your health plan provider.
An Archer MSA is a tax-exempt trust or custodial account that you set up with a U.S. financial institution (such as a bank or an insurance company) in which you can save money exclusively for future medical expenses
Flexible Spending Arrangements (FSAs)
A health flexible spending arrangement (FSA) allows employees to be reimbursed for medical expenses. FSAs are usually funded through voluntary salary reduction agreements with your employer. No employment or federal income taxes are deducted from your contribution. The employer may also contribute.
Health Reimbursement Arrangements (HRAs)
A health reimbursement arrangement (HRA) must be funded solely by an employer. The contribution cannot be paid through a voluntary salary reduction agreement on the part of an employee. Employees are reimbursed tax free for qualified medical expenses up to a maximum dollar amount for a coverage period. An HRA may be offered with other health plans, including FSAs.
Please see the IRS Publication for more information: HSA, HRA, MSA, FSA