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 take a look at some of our top-ranked mutual funds with the lowest fees.

Northern Large Cap Core (NOLCX) has a 0.45% expense ratio and 0.44% management fee. NOLCX is part of the Large Cap Blend section, and these mutual funds most often invest in firms with a market capitalization of $10 billion or more. By investing in bigger companies, these funds offer more stability, and are often well-suited for investors with a "buy and hold" mindset. With yearly returns of 14.59% over the last five years, this fund clearly wins.

Fidelity Advisor Value Strategies K (FVSKX Quick QuoteFVSKX - Free Report) : 0.59% expense ratio and 0.57% management fee. FVSKX is a Global - Equity mutual fund, which invests their assets in large markets, leveraging the global economy. FVSKX, with annual returns of 12.38% over the last five years, is a well-diversified fund with a long track record of success.

Putnam Small Cap Growth R6 (PLKGX): 0.73% expense ratio and 0.67% management fee. PLKGX is one of many Small Cap Growth mutual funds; these funds tend to create their portfolios around stocks with market capitalization of less than $2 billion. With a five-year annual return of 10.67%, 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.