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 take a look at some of our top-ranked mutual funds with the lowest fees.

BlackRock Impact US Equity Instl (BIRIX Quick QuoteBIRIX - Free Report) : 0.48% expense ratio and 0.4% management fee. BIRIX is part of the Large Cap Blend section, and these mutual funds most often invest in firms with a market capitalization of $10 billion or more. By investing in bigger companies, these funds offer more stability, and are often well-suited for investors with a "buy and hold" mindset. With annual returns of 15.14% over the last five years, this fund is a winner.

Fidelity New Millennium (FMILX Quick QuoteFMILX - Free Report) . Expense ratio: 0.86%. Management fee: 0.68%. FMILX is an All Cap Growth mutual fund investing in a wide variety of equities, no matter the size of the company and as long as the firm exhibits growth characteristics. This fund has managed to produce a robust 15.49% over the last five years.

Principal Mid Cap R4 (PMBSX Quick QuotePMBSX - Free Report) is an attractive large-cap allocation. PMBSX is a Mid Cap Growth mutual fund. These mutual funds choose companies with a stock market valuation between $2 billion and $10 billion. PMBSX has an expense ratio of 0.96%, management fee of 0.58%, and annual returns of 10.83% over the past five years.

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.