It is never too late to invest in mutual funds for retirement. As such, if you plan to invest in some of the best funds, the Zacks Mutual Fund Rank can provide you with valuable guidance.

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

Direxion Mo S&P 500 Bull 1.75X Inv (DXSLX Quick QuoteDXSLX - Free Report) has a 1.32% expense ratio and 0.75% management fee. DXSLX is classified as an Allocation Balanced fund, which seeks to invest in a balance of asset types, like stocks, bonds, and cash, and including precious metals or commodities is not unusual. With yearly returns of 13.96% over the last five years, this fund clearly wins.

MFS Mass Investors Growth Stock R6 (MIGNX Quick QuoteMIGNX - Free Report) is a stand out amongst its peers. MIGNX 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 five-year annualized performance of 12.65%, expense ratio of 0.37% and management fee of 0.33%, this diversified fund is an attractive buy with a strong history of performance.

T. Rowe Price New Horizons (PRNHX Quick QuotePRNHX - Free Report) is an attractive large-cap allocation. PRNHX is a Small Cap Growth mutual fund and tends to feature small companies in up-and-coming industries and markets. PRNHX has an expense ratio of 0.8%, management fee of 0.63%, and annual returns of 11.03% 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.