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

Fidelity Advisor Semiconductors M (FELTX Quick QuoteFELTX - Free Report) : 1.25% expense ratio and 0.52% management fee. With a much more diversified approach, FELTX--part of the Sector - Tech mutual fund category--gives investors a way to own a stake in the notoriously risky tech sector. FELTX has achieved five-year annual returns of an astounding 18.35%.

Hood River Small Cap Growth Institutional (HRSMX Quick QuoteHRSMX - Free Report) : 1.06% expense ratio and 0.9% management fee. HRSMX is a Small Cap Growth mutual fund and tends to feature small companies in up-and-coming industries and markets. HRSMX, with annual returns of 12.47% over the last five years, is a well-diversified fund with a long track record of success.

Jensen Quality Growth Fund R (JENRX Quick QuoteJENRX - Free Report) . Expense ratio: 1.26%. Management fee: 0.48%. Five year annual return: 11.59%. JENRX 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.

We hope that your investment advisor (if you use one) has you invested in one or all of the top-ranked mutual funds we've reviewed. But if that isn't the case, it might be time to have a conversation or reconsider this vitally important relationship.