The funds in our "Magnificent Retirement Mutual Funds" list are among the best managed and best performing mutual funds available. If you are just finding out about our Top-Ranked Funds list, we welcome you!

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 take a look at some of the highest Zacks Ranked mutual funds with the lowest fees.

Janus Henderson Forty S (JARTX - Free Report): 1.18% expense ratio and 0.63% management fee. JARTX is a part of the Large Cap Growth mutual fund category, which invest in many large U.S. companies that are expected to grow much faster compared to other large-cap stocks. JARTX has achieved five-year annual returns of an astounding 15.72%.

KP Large Cap Equity Institutional (KPLCX - Free Report): 0.3% expense ratio and 0.04% management fee. KPLCX 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. KPLCX, with annual returns of 10.35% over the last five years, is a well-diversified fund with a long track record of success.

Neuberger Berman Mid Cap Growth R6 (NRMGX - Free Report): 0.6% expense ratio and 0.55% management fee. NRMGX is a Mid Cap Growth mutual fund. These funds aim to target companies with a market capitalization between $2 billion and $10 billion that are also expected to exhibit more extensive growth opportunities for investors than their peers. With a five-year annual return of 10.35%, this fund is a well-diversified fund with a long track record of success.

These examples highlight the fact that there are some astonishingly good mutual funds out there. If your advisor has you in the good ones, bravo! If not, you may need to have a talk.