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.

If you are looking to diversify your portfolio, consider Neuberger Berman Large Cap Value Investor (NPRTX). NPRTX 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. This fund is a winner, boasting an expense ratio of 0.74%, management fee of 0.68%, and a five-year annualized return track record of 10.57%.

GMO U.S. Equity Allocation Fund ClIII (GMUEX Quick QuoteGMUEX - Free Report) is a stand out amongst its peers. GMUEX 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 five-year annualized performance of 14.55%, expense ratio of 0.49% and management fee of 0.46%, this diversified fund is an attractive buy with a strong history of performance.

RBC Emerging Mkts Value Equity R6 (RMVRX) is an attractive large-cap allocation. RMVRX is a Non US - Equity option, focusing their investments acoss emerging and developed markets, and can often extend across cap levels too. RMVRX has an expense ratio of 0.9%, management fee of 0.8%, and annual returns of 10.36% over the past five years.

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.