Citing the nearly 40% of American workers who have less than $10,000 in retirement savings, CNBC has declared the 401(k) a failure. But maybe a little more knowledge about 401(k)s and their secrets can help them work for you.First, smaller companies usually have higher 401(k) fees. Workers at large-cap companies are likely to pay less in fees. Second, those fees add up fast. For example, say you invested $25,000 over 30 years into your company’s 401(k) while paying maintenance fees of 0.35%. After 30 years, the fund will be at $143,587 dollars. Assuming a 6% annual return, it would have $136,716 remaining after removing maintenance fees. The same fund with maintenance fees of 0.94% would be worth only $127,027. Keeping fees low is a pivotal part of retiring comfortably, but even with high fees, it’s wise to invest in your 401(k) if your employer is offering a matching contribution. If your employer does not, compare its 401(k) to an IRA and determine which is the better option. You can borrow from your 401(k). It’s not typically advised, and you’ll have to repay the loan or be charged the taxes and penalties that come with an early distribution, but it’s an option worth considering in certain situations. If your account isn’t growing as fast as you hoped, the problem is probably you. The most disciplined savers own the 401(k)s with the biggest balances. On average, they put 14% of their salary into their savings. And finally, some 401(k)s have a self-directed option that enables employees to explore a wider range of lower-cost investments.