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 way to judge a mutual fund's quality over time is by analyzing its performance, diversification, and fees. Using the Zacks Mutual Fund Rank of over 19,000 mutual funds, we've identified three outstanding mutual funds that are ideally suited to help long-term investors pursue and achieve their retirement investing goals.

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

If you are looking to diversify your portfolio, consider DFA US Large Cap Growth Institutional (DUSLX Quick QuoteDUSLX - Free Report) . DUSLX 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. This fund is a winner, boasting an expense ratio of 0.18%, management fee of 0.15%, and a five-year annualized return track record of 13.48%.

Fidelity Select Tech Hardware (FDCPX Quick QuoteFDCPX - Free Report) : 0.73% expense ratio and 0.53% management fee. With a much more diversified approach, FDCPX--part of the Sector - Tech mutual fund category--gives investors a way to own a stake in the notoriously risky tech sector. With yearly returns of 16.09% over the last five years, FDCPX is an effectively diversified fund with a long reputation of solidly positive performance.

JPMorgan US Equity I (JUESX Quick QuoteJUESX - Free Report) : 0.69% expense ratio and 0.4% management fee. JUESX 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. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 13.61% over the last 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.