Roth IRAs have some interesting provisions that make them a little more liquid than other retirement accounts.

Roth IRAs contain after-tax contributions that actually remain accessible to you at any time, without tax or penalty. The stipulations on withdrawals are only concerned with earnings in the account, not the principal amount.

In order to withdraw earnings without paying a 10% penalty and income taxes, you must be at least 59½ and five years must have passed since you first began contributing.

The main exceptions to the early withdrawal rule are that you can withdraw up to $10,000 in earnings penalty-free to pay for your first home, and an unspecified amount can be withdrawn for educational expenses.