Investors interested in Medical stocks should always be looking to find the best-performing companies in the group. Has Thermo Fisher Scientific (TMO) been one of those stocks this year? Let's take a closer look at the stock's year-to-date performance to find out.Thermo Fisher Scientific is a member of our Medical group, which includes 845 different companies and currently sits at #3 in the Zacks Sector Rank. The Zacks Sector Rank includes 16 different groups and is listed in order from best to worst in terms of the average Zacks Rank of the individual companies within each of these sectors.The Zacks Rank is a proven model that highlights a variety of stocks with the right characteristics to outperform the market over the next one to three months. The system emphasizes earnings estimate revisions and favors companies with improving earnings outlooks. TMO is currently sporting a Zacks Rank of #2 (Buy).Within the past quarter, the Zacks Consensus Estimate for TMO's full-year earnings has moved 0.56% higher. This means that analyst sentiment is stronger and the stock's earnings outlook is improving.Our latest available data shows that TMO has returned about 22.65% since the start of the calendar year. Meanwhile, the Medical sector has returned an average of 1.89% on a year-to-date basis. As we can see, Thermo Fisher Scientific is performing better than its sector in the calendar year.To break things down more, TMO belongs to the Medical - Instruments industry, a group that includes 94 individual companies and currently sits at #77 in the Zacks Industry Rank. Stocks in this group have gained about 11.48% so far this year, so TMO is performing better this group in terms of year-to-date returns.Going forward, investors interested in Medical stocks should continue to pay close attention to TMO as it looks to continue its solid performance.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Thermo Fisher Scientific Inc. (TMO): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research