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 way to judge a mutual fund's quality over time is by analyzing its performance, diversification, and fees. Using the Zacks Mutual Fund Rank of over 19,000 mutual funds, we've identified three outstanding mutual funds that are ideally suited to help long-term investors pursue and achieve their retirement investing goals.

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

Goldman Sachs Small Cap Value Insights I (GSITX Quick QuoteGSITX - Free Report) : 0.84% expense ratio and 0.8% management fee. GSITX is a Small Cap Value mutual fund, investing in small companies with stock market valuation less than $2 billion. GSITX has achieved five-year annual returns of an astounding 14.59%.

American Funds Growth Portfolio F2 (GWPEX): 0.11% expense ratio and 0% management fee. GWPEX 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 11.58% over the last five years, GWPEX is an effectively diversified fund with a long reputation of solidly positive performance.

MassMutual Diversified Value R4 (MDDRX). Expense ratio: 1.02%. Management fee: 0.5%. Five year annual return: 14.78%. MDDRX is a Large Cap Value mutual fund, which invests in stocks with a market cap of $10 billion of more, but whose share prices do not reflect their intrinsic value.

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.