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.

Here are the funds that have achieved the Zacks Mutual Fund Rank #1 (Strong Buy) and have low fees.

Lord Abbett Growth Leaders I (LGLIX Quick QuoteLGLIX - Free Report) : 0.66% expense ratio and 0.51% management fee. LGLIX 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. LGLIX has achieved five-year annual returns of an astounding 12.39%.

Neuberger Berman Guardian R3 (NGDRX Quick QuoteNGDRX - Free Report) : 1.36% expense ratio and 0.74% management fee. NGDRX 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. NGDRX, with annual returns of 10.85% over the last five years, is a well-diversified fund with a long track record of success.

Oppenheimer Discovery R (ODINX Quick QuoteODINX - Free Report) : 1.26% expense ratio and 0.59% management fee. ODINX is a Small Cap Growth mutual fund and tends to feature small companies in up-and-coming industries and markets. With a five-year annual return of 10.14%, 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.