The deadline for making 2010 contributions to a health savings account (HSA) is April 15, 2011. Although the dollar limit on HSA contributions is determined monthly, HSA contributions for a taxable year may be made in one or more payments as long as the payments are not made before the beginning of the applicable tax year and not later than the original filing deadline (without extensions) for the individual's federal income tax return for that year (for example, April 15 for calendar year taxpayers).