The next time lawmakers decide to stimulate the economy, maybe they should arrange for a fleet of helicopters to drop $100 bills over populated areas.

That might not be a very efficient way of getting money in taxpayers' pockets. But given the events of the past couple of weeks, this much is clear: It's not easy for the government to give away money.

So far, the IRS has issued more than 45 million tax rebate payments, totaling nearly $41 billion. The payments, ranging from $300 to $600 a person, or $1,200 for a married couple, were distributed mainly by direct deposit to taxpayers who arranged to have their refunds delivered that way. The goal of the direct-deposit program was to get money into taxpayers' wallets as fast as possible.

But hundreds of thousands of taxpayers who had their e-filing or tax-preparation fees deducted from their refunds are belatedly discovering that they'll receive their checks by mail — even if they received direct deposit of their refunds.

The reason: If you arranged to have fees deducted from your refund, the tax-preparation company used a third-party bank to process the transaction. If, for example, you used TurboTax, the transaction was handled by Santa Barbara Bank & Trust. The IRS transmitted your refund to a temporary account at the bank, which deducted its own fees, sent the tax-preparation fees to the tax preparer and deposited the balance of your refund in your account, said Julie Miller, spokeswoman for TurboTax.

As a result, Miller said, the IRS has no actual bank account information for taxpayers who had their fees deducted from their refunds. Those taxpayers — along with taxpayers who applied for a refund-anticipation loan — will receive their checks by mail. The IRS began mailing paper checks on May 16 and will continue mailing them through July 11.

Miller said TurboTax posted a notice on its Web site on March 23, stating that taxpayers who had fees deducted from their refunds would receive their rebates by mail. That's when the IRS announced how it would handle those transactions, she said. By that time, though, many taxpayers had already filed their tax returns.

In fact, many taxpayers who were expecting a refund had filed their returns before Feb. 13, when the economic stimulus package was signed into law, says Amy McAnarney of H&R Block. Those taxpayers — and their tax preparers — had no way of knowing that deducting their fees would delay their tax rebates.

Wade Poulsen, 39, a procurement engineer in Spokane, Wash., said he thought he would receive his rebate by May 2. When it failed to arrive, he spent two days trying to get through to the IRS. When he finally reached a live person, he learned that his rebate would arrive by mail because he'd had his TurboTax fees deducted from his refund.

Meanwhile, many taxpayers who owed taxes this year are also discovering that their rebates will arrive by mail, even if they provided bank account information on their returns.

If you used direct debit to pay your tax bill, the IRS won't deposit your rebate in that account. You'll get your rebate check by mail.

NO CHECK IN THE MAIL

Other taxpayers are receiving a smaller-than-expected slice of the stimulus pie. Still others are discovering that they won't get a rebate at all. Some reasons: