Access to a 401(k) plan, or a retirement account like it such as the 403(b) or 457 plan depending on your line of work, is a privilege, as not all U.S. workers have access to these benefits. And not everyone who does have access participates in one, perhaps because they haven’t signed up, don’t know what benefits they’re offered or they can’t afford to contribute at the moment. 

Still, the potential advantages of these accounts shouldn’t be understated. Employer-sponsored retirement accounts are tax-deferred, which means contributions are made with pretax earnings, and many employers offer automatic contributions right from a worker’s earnings, so they never see the money “missing” from their paychecks. Some companies are even offering auto-escalation, so that every year the amount a person contributes increases incrementally, making it a painless way to save more.

The sooner someone starts saving in a retirement plan, the more they may have come retirement, since these investments grow with market returns and compound interest. 

Have a question about your own retirement concerns? Check out MarketWatch’s column “Help Me Retire”

There are a few caveats, however.

As companies celebrate National 401(k) Day, let’s look at how to make the most of your 401(k) by asking these important questions: 

Do I get a match? 

Many employers offer company matches to workers’ contributions up to a certain limit (such as 3% or 6%). There are often vesting stipulations, meaning employees must work at the company for a certain number of years to keep those employer contributions, but if they follow the rules, it’s essentially “free money.” 

Ask yourself if your company offers a match, what it is and how it works. Companies structure their matches differently. For example, one employer may say the first full 3 percentage points are 100% matched, and the following 3 percentage points are matched 50% – in this case, someone contributing 6% to her 401(k) plan would receive an employer match closer to 4.5%. 

Not everyone can meet the match, but any little bit helps. If you can, try to contribute as much as the full match, or as much as you can to get some of those extra benefits. 

How are my investments allocated? 

One of the most important considerations with a retirement account is how your money is invested. The wrong asset allocation could ravage your hard-earned dollars. The right one doesn’t mean you’ll constantly see your balance going up (thanks to market volatility), but it will help you stay on track and reach your retirement goals. 

Typical guidelines suggest the youngest of retirement savers should invest aggressively, even to the point of investing nearly all of their portfolios in equities. The closer to retirement one is, the more conservative the portfolio should become, though there should still be exposure to stocks (portfolios have to continue working for retirees for the decades they’ll be spending in retirement). There are plenty of other factors to consider as well, such as what investments your company is offering in its plan menu, and your risk tolerance. 

One easy way to keep track of your asset allocation is to invest in a target-date fund, which ties investments to a specific retirement year (i.e., 2030 or 2055) and automatically adjusts asset allocations as the years go on. It’s a simple approach, but doesn’t align with everyone’s goals, so consider working with a financial adviser or asking a professional at the investment firm where your portfolio is housed for more information and what may be best for you. 

What am I paying for my investments? 

Another crucial consideration: what you’re paying for your account. Look into what fees are associated with your retirement account, such as those for managing the portfolio or for the underlying investments themselves. Fees can erode the growth of a 401(k) plan. One study found the largest employers’ 401(k) plans charge well under 1% for the administration and investment components of these benefits, but fees can amount to much more. Still, assume your total cost is 1% of your assets – 1% of a $100,000 portfolio would be $1,000 you’re paying in fees for your retirement account every year. 

No plan is the same in this regard. If you’re unsure of where to find this information, call your Human Resources department or the firm managing your retirement account and ask – it’s your legal right to do so under the Department of Labor. If you’re not already receiving this information, ask HR or the company that holds the account how to sign up for these disclosures, since most plan participants get information about their accounts sent to them at least once a year. 

Want more actionable tips for your retirement savings journey? Read MarketWatch’s “Retirement Hacks” column

Is there a Roth component to my 401(k) benefit? 

Some companies offer a Roth version of the 401(k), where investors contribute with after-tax dollars but then can withdraw the money tax-free come retirement (compared to a traditional retirement account, where money is invested pretax and then taxed at withdrawal). Employees may want to split their contributions between the Roth and traditional so that they diversify their tax exposure later in life, but it’s hard to estimate what your tax situation will be in 20 or 30 years, or how tax rates may change even within the next decade. 

If you’re closer to retirement, or you’re extremely far from retirement, it may be easier to guess: young investors are often encouraged to invest at least some money in Roth accounts, since they’re likely in a lower tax bracket now than they will be later in life, whereas someone closer to retirement may want to stick to a traditional account if they’re at their peak earning years and anticipate less taxable income after they retire.