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 best way to shortlist great mutual funds is to ensure solid performance, diversification, and low fees. Some are better than others, but utilizing the Zacks Mutual Fund Rank, we have identified three mutual funds that could be solid additions to one's retirement portfolio.

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

Glenmede Disciplined US Eq (GTLOX Quick QuoteGTLOX - Free Report) has a 0.89% expense ratio and 0.55% management fee. GTLOX 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 10.77% over the last five years, this fund clearly wins.

LSV Global Managed Volatility Instl (LSVFX). Expense ratio: 0.75%. Management fee: 0.6%. LSVFX is a Global - Equity mutual fund investing in bigger markets like the U.S., Europe, and Japan; these kinds of funds aren't limited by geography. This fund has managed to produce a robust 11.97% over the last five years.

Invesco Energy R6 (IENSX): 0.83% expense ratio and 0.73% management fee. IENSX is a Sector - Energy mutual fund, which encompasses a wide range of vastly changing and vitally important industries throughout this massive global sector. With a five-year annual return of 24.97%, 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.