Elder Law is about understanding resources and tools available to you. The number of H.S.A. accounts increased by 16 percent year over year as of June 30, to more than 21 million. Assets held in the accounts grew 23 percent, to just under $43 billion. Contributions can be deducted pretax from your paycheck, lowering your taxable income; any interest or investment gains on the money is tax free; and withdrawals from the account are tax free, as long you spend the money on eligible items. And if you change jobs, the H.S.A. moves with you.