Investing in mutual funds for retirement is never too late. And the Zacks Mutual Fund Rank can be an excellent tool for investors looking to invest in the best funds.

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 take a look at some of our top-ranked mutual funds with 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 an Allocation Balanced mutual fund. Allocation Balanced funds look to invest across asset types, like stocks, bonds, and cash, and including precious metals or commodities is not unusual; these funds are mostly categorized by their respective asset allocation. With yearly returns of 11.28% over the last five years, this fund clearly wins.

Deutsche Science and Technology A (KTCAX Quick QuoteKTCAX - Free Report) . Expense ratio: 0.91%. Management fee: 0.45%. KTCAX is a Sector - Tech mutual fund, allowing investors to own a stake in a notoriously volatile sector with a much more diversified approach. This fund has managed to produce a robust 13.75% over the last five years.

MFS Growth Fund R4 (MFEJX Quick QuoteMFEJX - Free Report) . Expense ratio: 0.6%. Management fee: 0.49%. Five year annual return: 11.07%. MFEJX 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.

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.