JOE THE PLUMBER and his tax worries have suddenly become a major feature of the campaign.

But from the sound of things Joe doesn't need a new president – he needs a new accountant.

The reason? The tax code already contains some incredible deals for small businesss owners and independent contractors.

(Of course Joe may have some other matters to deal with first. He doesn't yet have a plumber's license. And there are reports he still has a personal tax lien outstanding.)

But if he sorts out those issues and is able to buy the small plumbing company where he works, he'll have access to some great tax shelters.

Of course he'll also be able to write off a lot of business expenses. But that's just the start.

Special plans like SEP IRAs, self-employed or "solo" 401ks, and defined benefit pensions let the self-employed slash their taxable income still further and save the money in a tax-deferred retirement account each year.

We're not just talking to the $15,500 limits available to ordinary folk working for a salary. We're looking at limits of $46,000 – or more.

"These are fantastic ways to shelter your profits," says Karin Maloney Stifler, a financial planner in Joe's home state of Ohio. "Of course you have to be profitable to take advantage."

Joe, according to reports, is trying to buy out the plumbing business he works for. It makes, he says, $250,000 a year.

Joe: If you are self-employed, a "solo" or self-employed 401(k) plan will let you deduct $15,500 from your taxable income and salt it away in a tax-deferred retirement account, just like any other 401k.

But then, because you're running your own business, you can deduct even more – up to a total of $46,000 this year.

For some people the SEP or self-employed IRA may be a better alternative. It also has a limit of $46,000.

Joe's only 34 right now, but when he passes 50 he can shelter even more of his income.

And that's not all.

For self-employed contractors nearing retirement, the best shelter of all may be to set up a defined benefit company pension plan. The law may allow you to shelter huge amounts of your salary from tax each year thanks to incredible catch-up provisions. The limits are generous: You can save enough to ensure yourself a retirement income of $180,000 a year.

Bob Glovsky, head of Mintz Levin Financial Advisors, says that "in some cases you can actually shelter almost everything you earn."

Obviously we're simplifying things here. There are details to work through. If you have full-time staff it can complicate matters. A SEP IRA or solo 401k is pretty cheap to set up, but the defined benefit pension plan is more complex and expensive, though Mr Sard says costs can start at around $1,500 a year.

Write to Brett Arends at brett.arends@wsj.com