(FORTUNE Magazine) – I'm 39 and am planning to quit my job and start my own business. I was wondering, Is there any way I could tap the money I've accumulated in my 401(k) and IRA accounts without triggering any tax consequences?

Yes, it's possible--but you'll have to tread very carefully, says Martin Nissenbaum, the national director of personal income-tax planning at Ernst & Young. If you want to use your 401(k) plan savings to invest in a business, you'll first have to roll the funds over to an IRA, since 401(k) plans do not allow this type of investment. You'll also have to make sure that the rollover IRA is the "self-directed" kind, one in which the plan custodian doesn't limit your investment options. You can then transfer money directly into the new business's bank account, provided you adhere to IRS regulations.

This is where things can get tricky, warns Nissenbaum. The IRS has many rules dictating what it considers "prohibited transactions" between you and your IRA. In essence, this involves buying and selling property to and from yourself within your IRA. And if you enter into one of these forbidden deals, your entire IRA will probably be disqualified, resulting in a full tax hit and a 10% early-distribution penalty. "This makes the timing of the investment by the IRA especially critical," says Nissenbaum. You may, for example, be able to use your IRA funds to get your venture started. But depending on your ownership stake, you may be unable to tap the IRA for additional funds. The bottom line: Don't try this without first consulting a tax professional.

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