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

If you are looking to diversify your portfolio, consider Invesco Discovery A (OPOCX Quick QuoteOPOCX - Free Report) . OPOCX is a Small Cap Growth mutual fund and tends to feature small companies in up-and-coming industries and markets. This fund is a winner, boasting an expense ratio of 1.03%, management fee of 0.6%, and a five-year annualized return track record of 11.24%.

Congress Large Cap Growth Fund (CAMLX Quick QuoteCAMLX - Free Report) : 0.94% expense ratio and 0.5% management fee. CAMLX is a Large Cap Growth mutual fund, and these funds invest in many large U.S. firms that are projected to grow at a faster rate than their large-cap peers. With yearly returns of 15.86% over the last five years, CAMLX is an effectively diversified fund with a long reputation of solidly positive performance.

Eagle MLP Strategy I (EGLIX Quick QuoteEGLIX - Free Report) . Expense ratio: 1.41%. Management fee: 1.25%. Five year annual return: 10.92%. EGLIX is a Sector - Energy mutual fund, which encompasses a wide range of vastly changing and vitally important industries throughout this massive global sector.

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.