Is there any major reason to roll over my old 401K?

[D Bopp]

I stopped working for a company in 2011 and have a 401k with them through Fidelity.   It's performed well and I have access to all the low cost Spartan funds. 
Other than not wanting my money in an old company 401k, is there any reason why I shouldn't just leave it in there?   

[solon]

Generally you want your money under your control. What happens if the old company changes 401k providers? Would you get lost in the shuffle? What happens if they go out of business?

Plus, if you leave more than one job (like many of us have) you could end up with several old 401ks at different places. Whenever I leave a company, I roll the old 401k into a personal IRA. At any given point, I have only two retirement plans: the current company's retirement account, and the IRA containing all my old retirement money.

[seattlecyclone]

I like to consolidate accounts when possible for the sake of simplicity. But that's more of a personal choice. If you like the funds you're invested in right now, there's certainly no hurry to switch. If the 401(k) provider changes you can always take your money out at that time.

[NoraLenderbee]

There's no real reason not to roll it over to an IRA at Fidelity. You can keep it in the same funds, since they are all Fidelity funds. Just contact Fidelity. They make it very easy and there should be no cost.

[nanu]

However, if you're making over the threshold of contributing to a Roth IRA and want to do a Backdoor Roth IRA then
having money in a traditional IRA (as opposed to an old 401K) will make the Backdoor Roth worse.

Check out the part under "Caution": http://www.bogleheads.org/wiki/Backdoor_Roth_IRA