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 easiest, most reliable way to judge a mutual fund's quality over time is by analyzing its performance, diversification, and fees. The Zacks Mutual Fund Rank, which covers over 19,000 mutual funds, has helped us identify three outstanding options that are perfect for any long-term investors' portfolios that is retirement-focused.

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

Wells Fargo Diversified Capital Builder I

(EKBYX Quick QuoteEKBYX - Free Report) has a 0.78% expense ratio and 0.62% management fee. EKBYX 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 12.89% over the last five years, this fund clearly wins.

Principal Capital Appreciation R5

(PCAQX Quick QuotePCAQX - Free Report) is a stand out amongst its peers. PCAQX 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 five-year annualized performance of 15.87%, expense ratio of 0.69% and management fee of 0.43%, this diversified fund is an attractive buy with a strong history of performance.

TIAA-CREF Large Cap Value Retirement

(TRLCX Quick QuoteTRLCX - Free Report) is an attractive large-cap allocation. TRLCX is a part of the Large Cap Value category, and invests in equities with a market capitalization of $10 billion or more, but whose share prices do not reflect their intrinsic value. TRLCX has an expense ratio of 0.66%, management fee of 0.4%, and annual returns of 12.51% 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.