There is never a wrong time to invest in mutual funds for retirement. So, if you're still looking for the best mutual funds, the Zacks Mutual Fund Rank can be a great guide.

The easiest, most reliable way to judge a mutual fund's quality over time is by analyzing its performance, diversification, and fees. The Zacks Mutual Fund Rank, which covers over 19,000 mutual funds, has helped us identify three outstanding options that are perfect for any long-term investors' portfolios that is retirement-focused.

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

American Funds Fundamental Investors 529A (CFNAX): 0.62% expense ratio and 0.24% management fee. CFNAX 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 16.34% over the last five years, this fund is a winner.

Congress Small Cap Growth Retail (CSMVX): 1.25% expense ratio and 0.85% management fee. CSMVX is a Small Cap Growth mutual fund and tends to feature small companies in up-and-coming industries and markets. CSMVX, with annual returns of 15.01% over the last five years, is a well-diversified fund with a long track record of success.

T. Rowe Price International Value Equity Adviser (PAIGX). Expense ratio: 1.09%. Management fee: 0.63%. Five year annual return: 15.1%. PAIGX is a Non US - Equity option, focusing their investments acoss emerging and developed markets, and can often extend across cap levels too.

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.

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This article originally published on Zacks Investment Research (zacks.com).

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