The funds in our "Magnificent Retirement Mutual Funds" list are some of the top-performing, best managed funds available. If you're already invested in them, congratulations! If you're not, don't worry - it's never too late to start getting the advantages of these outstanding funds for your retirement.

How can you tell a good mutual fund from a bad one? It's pretty basic: if the fund is diversified, has low fees, and shows strong performance, it's a keeper. Of course, there's a wide range, but using our Zacks Rank, we've found three mutual funds that would be great additions to any long-term retirement investors' portfolios.

Let's learn about some of Zacks' highest ranked mutual funds with low fees you may want to consider.

JPMorgan US Equity Fund R6 (JUEMX Quick QuoteJUEMX - Free Report) : 0.44% expense ratio and 0.4% management fee. JUEMX is classified as a Large Cap Blend fund. More often than not, Large Cap Blend mutual funds invest in companies with a market cap of over $10 billion. Buying stakes in bigger companies offer these funds more stability, and are well-suited for investors with a "buy and hold" mindset. With annual returns of 11% over the last five years, this fund is a winner.

AB Large Cap Growth I (ALLIX Quick QuoteALLIX - Free Report) : 0.62% expense ratio and 0.51% management fee. ALLIX is a Large Cap Growth option; these mutual funds purchase stakes in numerous large U.S. companies that are expected to develop and grow at a faster rate than other large-cap stocks. With yearly returns of 16.32% over the last five years, ALLIX is an effectively diversified fund with a long reputation of solidly positive performance.

Van Eck International Investors Gold I (INIIX Quick QuoteINIIX - Free Report) . Expense ratio: 1%. Management fee: 0.73%. Five year annual return: 16.92%. Sector - Precious Metal funds like INIIX normally invest in stocks focused on the mining and production of precious metals such as gold, silver, platinum, and palladium.

So, there you have it - if your advisor has you invested in any of our "Magnificent Retirement Mutual Funds," they are certainly earning their keep. If not, you may want to look elsewhere.

Do You Know the Top 9 Retirement Investing Mistakes?

Investing in underperforming mutual funds is just one of the key errors that can derail your retirement plans.

To learn more, read our just-released report: 9 Retirement Mistakes You Need to Avoid.