The IRS says:
Generally, distributions of elective deferrals cannot be made until one of the following occurs:
Tax on early distributions. If a distribution is made to you under the plan before you reach age 59½, you may have to pay a 10% additional tax on the distribution. This tax applies to the amount received that you must include in income.
- You die, become disabled, or otherwise have a severance from employment.
- The plan terminates and no successor defined contribution plan is established or maintained by the employer.
- You reach age 59½ or incur a financial hardship.
It then lists all the well known exceptions to the application of the penalty. Which include SEPPs and withdrawals made after separation of service provided you didn't separate from your employer until the calendar year you turn 55, etc.
The exact wording is:
Made to a participant after separation from service if the separation occurred during or after the calendar year in which the participant reached age 55...
Source: 401(k) Resource Guide - Plan Participants - General Distribution Rules
TR2010, if you're not staying until 55, then it sounds like rolling your 401(k) into a traditional IRA and then doing a 72(t) SEPP might be what you are looking for. Or you could go with Brewer's advice (wink, wink), but I haven't done any research in that area. SEPPs are not overly complicated to do, but if you make a mistake it gets to be real expensive in penalties. I really like this site and have found it very informative:
Welcome to 72t on the Net
Edit: Don't know if you are ready to ER now (Ala, I really can't stand this place anymore), if you can do a little less than two more years, or if you can do what Brewer suggests, but I think if I was in your position I would much rather do the "after 55" plan and stick with the 401(k). Mostly because withdrawals from the SEPP have no flexibility once you start, but the distributions from your 401(k) can be either periodic or non-periodic. Flexibility is a nice thing to have.