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.

Thrivent Small Cap Stock A

(AASMX Quick QuoteAASMX - Free Report) has a 1.03% expense ratio and 0.63% management fee. AASMX is a Small Cap Blend mutual fund, and usually targets stocks with market caps of less than $2 billion, letting investors diversify their funds among other kinds of small-cap equities. With yearly returns of 13.48% over the last five years, this fund clearly wins.

Invesco Comstock Y

(ACSDX Quick QuoteACSDX - Free Report) is a stand out amongst its peers. ACSDX is a Large Cap Value mutual fund, which invests in stocks with a market cap of $10 billion of more, but whose share prices do not reflect their intrinsic value. With five-year annualized performance of 14.47%, expense ratio of 0.56% and management fee of 0.38%, this diversified fund is an attractive buy with a strong history of performance.

Principal Capital Appreciation I

(PWCIX Quick QuotePWCIX - Free Report) . Expense ratio: 0.45%. Management fee: 0.43%. Five year annual return: 16.16%. PWCIX 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.

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.