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.

How can you tell a good mutual fund from a bad one? It's pretty basic: if the fund is diversified, has low fees, and shows strong performance, it's a keeper. Of course, there's a wide range, but using the Zacks Mutual Fund Rank, we've found three mutual funds that would be great additions to any long-term retirement investors' portfolios.

Let's take a look at some of our top-ranked mutual funds with the lowest fees.

Brown Advisory Flexible Equity Institutional (BAFFX Quick QuoteBAFFX - Free Report) : 0.54% expense ratio and 0.43% management fee. BAFFX 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 annual returns of 10.69% over the last five years, this fund is a winner.

Ivy Large Cap Growth N (ILGRX Quick QuoteILGRX - Free Report) is a stand out amongst its peers. ILGRX 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 five-year annualized performance of 14.03%, expense ratio of 0.64% and management fee of 0.6%, this diversified fund is an attractive buy with a strong history of performance.

JPMorgan US Equity I (JUESX Quick QuoteJUESX - Free Report) : 0.69% expense ratio and 0.4% management fee. JUESX is part of the Large Cap Blend section, and these mutual funds most often invest in firms with a market capitalization of $10 billion or more. By investing in bigger companies, these funds offer more stability, and are often well-suited for investors with a "buy and hold" mindset. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 12.12% 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.