FSA (flexible spending arrangement): usually funded by the employee through salary reduction. A health FSA is generally use-it-or-lose-it: money left at the end of the plan year is forfeited unless the plan allows a limited carryover or a grace period of up to 2½ months, but not both. The employer cannot refund the balance to the employee.

HRA (health reimbursement arrangement): funded solely by the employer. Employees cannot add money to it, not even through a voluntary salary reduction.

HSA (health savings account): to contribute, the owner must be covered by a high deductible health plan (HDHP). The owner, the employer or any other person may contribute. Unused money carries over year after year, and the account stays with the employee after a change of employers.