There is never a wrong time to invest in mutual funds for retirement. So, if you're still looking for the best mutual funds, the Zacks Mutual Fund Rank can be a great guide.

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.

Brown Advisory Flexible Equity Investor (BIAFX Quick QuoteBIAFX - Free Report) has a 0.69% expense ratio and 0.43% management fee. BIAFX is classified as an Allocation Balanced fund, which seeks to invest in a balance of asset types, like stocks, bonds, and cash, and including precious metals or commodities is not unusual. With yearly returns of 10.98% over the last five years, this fund clearly wins.

Buffalo Large Cap Fund (BUFEX Quick QuoteBUFEX - Free Report) . Expense ratio: 0.95%. Management fee: 0.75%. BUFEX is a part of the Large Cap Growth mutual fund category, which invest in many large U.S. companies that are expected to grow much faster compared to other large-cap stocks. This fund has managed to produce a robust 11.14% over the last five years.

Neuberger Berman Guardian Investor (NGUAX Quick QuoteNGUAX - Free Report) . Expense ratio: 0.83%. Management fee: 0.74%. Five year annual return: 13.39%. NGUAX is a Large Cap Value mutual fund, which invests in stocks with a market cap of $10 billion of more, but whose share prices do not reflect their intrinsic value.

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.