NEW YORK (MainStreet) — Instead of worrying about that old 401(k) plan you've got floating around out there, why don't you do something about it? Here are three solid options for your erstwhile assets. 

1. Roll it into an IRA

If you move your money into an IRA you will have access to the "entire universe" of investment possibilities, says Terry Dunne, head of the rollover solutions group at financial services firm Millennium Trust.

There's also something to be said for getting all your money in one place. If you've had several jobs that offered 401(k) plans and they're sitting unattended, consolidating them into an IRA allows you to be much more organized, Dunne says.

"What's going to be easier to manage in the years to come, three or four different 401(k) plans or one IRA?" he asks. "If you leave a company, you might forget you had a retirement benefit, you move and suddenly they can no longer track you, and you don't know who to contact. With an IRA, it's much less likely you will forget or permanently lose that money."

Also, keep in mind that if you aren't getting your statements, someone else may be getting them at your old address.

"Anytime you're not connected to your money, it's dangerous," Dunne says.

If you're interested in managing your own retirement accounts, an IRA may be the best option.

"If you roll your money into an IRA, that's between you and the financial institution," Dunne says. "They're going to be better set up to answer any questions as it relates to your money."

By leaving your money in a 401(k), you're more likely to let your investments stagnate than if you transfer the funds to an IRA where you can get more actively involved.

"It may not make sense for you to be in the same investments that you were five years ago, but if you aren't in control of your plan, that's exactly where you'll be. With an IRA you can select an investment that is appropriate as your age and liquidity changes."

When setting up an IRA, note that there may be an initial fee to set up the plan and/or an annual fee charged by the financial institution, but these will be minimal.

"The investor just needs to talk to the people who help them open the IRA and ask if there are any extra costs," Dunne says.

2. Roll your money into a new 401(k) plan with your new employer

If you're immediately heading into a new job that offers a 401(k) plan, consider rolling over your current 401(k) into the new plan, says Neil Smith, executive vice president of independent college and retirement savings provider Ascensus.

"This is something you should be thinking about as you leave a job. If you have an opportunity for those balances to travel with you, take it," he says.

If you're leaving a job and not immediately heading to a new company, maintain your account information until you start a new position, Dunne says. It's not enough to keep in touch with the HR department at your former company. You must keep notices from the financial institution in charge of your 401(k)

"The people who are in the retirement plan service group at your company may also leave, so you won't be able to call and connect with them again," he says.

Once you start a job, the HR department will be able to give you all the particulars and requirements for rolling your old plan into your current one.

3. Leave your money in your 401(k), but keep an eye on it

"Whether or not you should roll your 401(k) over is a very hot topic right now," says Charles Wareham, financial advisor and CEO of asset management firm Valark Financial Services. Low fees are just one advantage to leaving your money untouched.

"It's a pretty cheap place to keep your money," Wareham says. "You have group purchasing power, and you're still considered part of that group even once you leave the company."

Before you stick with your current plan, assess whether it offers broad investment choices, good performance and reasonable fees, Smith says.

"If you're an engaged investor who likes making decisions, just make sure you are maximizing whatever features are in your plan," he explains.

Note that there are no fees associated with no longer working at the company — just a routine account maintenance fee that everyone pays.

"The cost of managing the plan is spread out over so many members of the 401(k), there are benefits to leaving your money there," Wareham says.

Many people with a 401(k) from a previous job immediately choose to move the money into an IRA, Dunne says, but before any decisions are made, it's best to talk to a plan sponsor.

"Get a handle on the costs you are likely to incur and compare that to the fees you would have if you moved your money into an IRA and then invested in the same investments or different investments," he says. "In many cases, the one with the lower costs is the one you'd prefer to be in."

— Written by Kathryn Tuggle for MainStreet

Follow Kathryn on Twitter @KathrynTuggle