For those looking to find strong Medical stocks, it is prudent to search for companies in the group that are outperforming their peers. Has UnitedHealth Group (UNH) been one of those stocks this year? A quick glance at the company's year-to-date performance in comparison to the rest of the Medical sector should help us answer this question.UnitedHealth Group is a member of our Medical group, which includes 902 different companies and currently sits at #14 in the Zacks Sector Rank. The Zacks Sector Rank considers 16 different groups, measuring the average Zacks Rank of the individual stocks within the sector to gauge the strength of each group.The Zacks Rank is a proven system that emphasizes earnings estimates and estimate revisions, highlighting a variety of stocks that are displaying the right characteristics to beat the market over the next one to three months. UNH is currently sporting a Zacks Rank of #2 (Buy).Within the past quarter, the Zacks Consensus Estimate for UNH's full-year earnings has moved 2% higher. This means that analyst sentiment is stronger and the stock's earnings outlook is improving.Based on the latest available data, UNH has gained about 4.96% so far this year. In comparison, Medical companies have returned an average of 1.06%. This means that UnitedHealth Group is performing better than its sector in terms of year-to-date returns.Looking more specifically, UNH belongs to the Medical - HMOs industry, which includes 10 individual stocks and currently sits at #32 in the Zacks Industry Rank. On average, this group has lost an average of 2.86% so far this year, meaning that UNH is performing better in terms of year-to-date returns.Investors with an interest in Medical stocks should continue to track UNH. The stock will be looking 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 UnitedHealth Group Incorporated (UNH): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research