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.

Here are the funds that have achieved the Zacks Mutual Fund Rank #1 (Strong Buy) and have low fees.

Fidelity Advisor Semiconductors I (FELIX Quick QuoteFELIX - Free Report) : 0.74% expense ratio and 0.53% management fee. FELIX is a Sector - Tech mutual fund, allowing investors to own a stake in a notoriously volatile sector with a much more diversified approach. With annual returns of 28.8% over the last five years, this fund is a winner.

JPMorgan Growth Advantage R5 (JGVRX Quick QuoteJGVRX - Free Report) . Expense ratio: 0.65%. Management fee: 0.55%. JGVRX 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 has managed to produce a robust 16.95% over the last five years.

Nicholas Fund (NICSX Quick QuoteNICSX - Free Report) . Expense ratio: 0.71%. Management fee: 0.65%. Five year annual return: 14.07%. NICSX is classified as a Large Cap Blend fund. More often than not, Large Cap Blend mutual funds invest in companies with a market cap of over $10 billion. Buying stakes in bigger companies offer these funds more stability, and are well-suited for investors with a "buy and hold" mindset.

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.