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

Amana Growth Investor (AMAGX Quick QuoteAMAGX - Free Report) has a 0.9% expense ratio and 0.62% management fee. AMAGX 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 yearly returns of 13.94% over the last five years, this fund clearly wins.

Dreyfus Appreciation Fund Y (DGYGX Quick QuoteDGYGX - Free Report) . Expense ratio: 0.59%. Management fee: 0.55%. DGYGX 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. This fund has managed to produce a robust 10.68% over the last five years.

Fidelity Select Semiconductors (FSELX Quick QuoteFSELX - Free Report) : 0.68% expense ratio and 0.53% management fee. With a much more diversified approach, FSELX--part of the Sector - Tech mutual fund category--gives investors a way to own a stake in the notoriously risky tech sector. With a five-year annual return of 16.62%, this fund is a well-diversified fund with a long track record of success.

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.