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

AB Large Cap Growth I (ALLIX Quick QuoteALLIX - Free Report) : 0.55% expense ratio and 0.48% management fee. ALLIX 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 annual returns of 13.03% over the last five years, this fund is a winner.

Janus Henderson Global Life Science I (JFNIX Quick QuoteJFNIX - Free Report) : 0.77% expense ratio and 0.64% management fee. JFNIX is classified as a Sector - Health fund. Healthcare is one of the biggest sectors of the American economy, and these kinds of mutual funds provide a great opportunity to invest in this industry. With yearly returns of 10.45% over the last five years, JFNIX is an effectively diversified fund with a long reputation of solidly positive performance.

T. Rowe Price Capital Appreciation Fund (PRWCX Quick QuotePRWCX - Free Report) is an attractive large-cap allocation. PRWCX is an All Cap Value mutual fund, which invests in small, medium, and large-cap companies, though they end up focusing on bigger firms due to percentage of assets. PRWCX has an expense ratio of 0.71%, management fee of 0.59%, and annual returns of 10.33% over the past 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.