There is never a wrong time to invest in mutual funds for retirement. So, if you're still looking for the best mutual funds, the Zacks Mutual Fund Rank can be a great guide.

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 learn about some of Zacks' highest ranked mutual funds with low fees you may want to consider.

JPMorgan Intrepid Growth Fund C (JCICX Quick QuoteJCICX - Free Report) : 1.34% expense ratio and 0.3% management fee. JCICX 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. With annual returns of 16.2% over the last five years, this fund is a winner.

American Funds Mutual Fund 529F (CMLFX Quick QuoteCMLFX - Free Report) : 0.44% expense ratio and 0.23% management fee. CMLFX is a Large Cap Value fund. These funds invest in stocks with a market cap of $10 billion of more, but whose share prices do not reflect their intrinsic value. CMLFX, with annual returns of 10.44% over the last five years, is a well-diversified fund with a long track record of success.

Wells Fargo Special Mid Cap Value Admiral (WFMDX Quick QuoteWFMDX - Free Report) is an attractive large-cap allocation. WFMDX is a Mid Cap Value mutual funds that aims to target medium-sized companies that possess strong value and income opportunities for investors. WFMDX has an expense ratio of 1.05%, management fee of 0.66%, and annual returns of 11.81% 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.