The Tax Increase Prevention and Reconciliation Act of 2005 extended several popular provisions of the Jobs and Growth Tax Relief Reconciliation Act of 2003. Not only did TIPRA renew the low tax rates on qualified dividends and long-term capital gains rates that so many investors hold dear today (it seems like a lifetime ago that dividends were taxed at ordinary income tax rates!), but it also lifted the income restrictions for converting a traditional IRA to Roth, starting in 2010. Before 2010, you could only convert traditional IRAs to Roth if your adjusted gross income was below $100,000.
And with the lifting of those income limits--but not the income limits governing who can contribute to a Roth IRA directly--the "backdoor Roth IRA" was born. The backdoor Roth IRA strategy is often touted as an easy way for high-income folks who are otherwise shut out of direct Roth IRA contributions because they earn too much to get at least some assets into the Roth column without having to pay a big tax bill. The basic idea is to fund a traditional IRA, for which there are no income limits (assuming you're not deducting the contribution), then convert to a Roth--again, no income limits thanks to TIPRA.