If you're invested in any of the funds in our "Magnificent Retirement Mutual Funds" list, congratulations on owning some of the best managed and top-performing mutual funds. If you are lucky enough to discover our list of Top-Ranked Funds for the first time, it's never too late to start investing with the best, especially when it comes to your retirement.

Great performance, diversification, and low fees: it's a pretty simple formula for a great mutual fund. Some are better than others, but utilizing our Zacks Rank, we have identified three mutual funds that would make great additions to long-term investors' portfolios.

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

General Electric RSP Mutual Fund : 0.14% expense ratio and 0.1% management fee. GESSX 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 annual returns of 10.75% over the last five years, this fund is a winner.

MSIF International Advantage A (MFAPX Quick QuoteMFAPX - Free Report) : 1.28% expense ratio and 0.8% management fee. MFAPX is a Global - Equity mutual fund, which invests their assets in large markets, leveraging the global economy. MFAPX, with annual returns of 13.54% over the last five years, is a well-diversified fund with a long track record of success.

Janus Henderson Enterprise Institutional (JAAGX Quick QuoteJAAGX - Free Report) . Expense ratio: 0.72%. Management fee: 0.64%. Five year annual return: 14.98%. JAAGX is a Mid Cap Growth mutual fund. These mutual funds choose companies with a stock market valuation between $2 billion and $10 billion.

There you have it. If your financial advisor had you put your money into any of our "Magnificent Retirement Mutual Funds," then they've got you covered. If not, you may need to talk.

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.