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.

William Blair Large Cap Growth N (LCGNX Quick QuoteLCGNX - Free Report) has a 0.9% expense ratio and 0.6% management fee. LCGNX 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 16.78% over the last five years, this fund clearly wins.

Principal Mid Cap R5 (PMBPX Quick QuotePMBPX - Free Report) . Expense ratio: 0.84%. Management fee: 0.58%. PMBPX is a Mid Cap Growth mutual fund. These funds aim to target companies with a market capitalization between $2 billion and $10 billion that are also expected to exhibit more extensive growth opportunities for investors than their peers. This fund has managed to produce a robust 10.97% over the last five years.

Fidelity Advisor Value Strategies A (FSOAX Quick QuoteFSOAX - Free Report) : 1.15% expense ratio and 0.68% management fee. FSOAX is a Global - Equity mutual fund. These funds invest in large markets like the U.S., Europe, and Japan, and operate with very few geographical limitations. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 12.48% over the last five years.

There you have it. If your financial advisor had you put your money into any of our top-ranked funds, then they've got you covered. If not, you may need to talk.