Those of us born with the "P" gene (for procrastination) are probably just peering into our tax files. This year, the lure of the stimulus payment, or rebate, might actually encourage some traditional laggards to finish on time. After all, the IRS says that folks whose returns are processed by April 15 will get their rebates as early as May 2.

So, tax sleepyheads might ask, why not just do the best we can to file on time, get the rebate, and catch mistakes later with an amended return?

Here's why that strategy is a loser:

• If you haven't already filed, you probably have missed the cutoff for having your return processed by the IRS in time for the May rebate distribution, says Eric Smith, an IRS spokesman.

• Filing the amended return, 1040X, is a pain. The three-column form isn't easy to navigate, and unless your return is simple, you're going to need a professional's help, says Bill Malgieri, a CPA in Elsmford, N.Y.  "It's not something the average taxpayer will do, especially if something on the return is relatively complicated," he says.

Malgieri and Smith agree that it's best to file for an extension, using IRS Form 4868, pay what you think you owe by April 15, and then file 1040 by the final deadline of October 15. While it's true you'll have to wait for your rebate--and any refund--you'll avoid the complications of an amended return. "I’ve seen too many situations where people rush and don’t do it right," Malgieri says. "That's what the extension is really for."