After you open your HSA, making contributions helps you build a balance to assist with current and future health care expenses. Anyone, including your employer or family members, may contribute to your HSA. You can make contributions by payroll deduction (if available) or by after-tax contributions.
Payroll deductions: If your employer offers the option, you may specify a regular contribution to be deducted from your paycheck. This contribution will be made before Social Security, federal, and most state income taxes are deducted. After-tax contributions: You may choose to make all or part of your annual account contributions to your HSA by making “after-tax” contributions to your account. These contributions may be deducted on your income tax return, using IRS Form 1040 and Form 8889.
Employers may make contributions to your account as well; while you do not take a deduction for these contributions, they are excluded from your gross income.
Note: You will use IRS Form 1040 for your HSA contributions, not the short form 1040A or 1040EZ. This deduction is taken “above the line”: you do not need to itemize contributions on Schedule A in order to claim the deduction for HSA contributions.
You are eligible to make contributions to your HSA as long as you meet the definition of an “eligible individual” as listed in the question, “Who is eligible to open an HSA?” If you no longer participate in a high-deductible health plan or enroll in Medicare, you can no longer contribute new funds to your HSA account.