Investing in mutual funds for retirement is never too late. And the Zacks Mutual Fund Rank can be an excellent tool for investors looking to invest in the best funds.

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 break down some of the mutual funds with the top Zacks Mutual Fund Rank and the lowest fees.

DFA US Micro Cap Institutional

(DFSCX Quick QuoteDFSCX - Free Report) : 0.41% expense ratio and 0.38% management fee. DFSCX is a Small Cap Blend mutual fund that usually targets companies with a market capitalization of less than $2 billion. DFSCX has achieved five-year annual returns of an astounding 12.11%.

Fidelity Series International Growth

(FIGSX Quick QuoteFIGSX - Free Report) : 0.01% expense ratio and 0% management fee. FIGSX is a Non US - Equity option, focusing their investments acoss emerging and developed markets, and can often extend across cap levels too. With yearly returns of 10.13% over the last five years, FIGSX is an effectively diversified fund with a long reputation of solidly positive performance.

Franklin Natural Resources Adviser

(FNRAX Quick QuoteFNRAX - Free Report) : 0.76% expense ratio and 0.52% management fee. FNRAX is classified as a Sector - Energy mutual fund. Throughout the massive global energy sector, these funds hold a wide range of quickly changing and vitally important industries. With a five-year annual return of 11.38%, this fund is a well-diversified fund with a long track record of success.

There you have it. If your financial advisor had you put your money into any of our top-ranked funds, then they've got you covered. If not, you may need to talk.