This week, four health care provider stocks are improving their overall rating on Portfolio Grader. Each of these rates an “A” (“strong buy”) or “B” overall (“buy”).

LCA-Vision (LCAV) ups its rating to a B (“buy”) this week after earning a C (“hold”) in the week before. LCA-Vision provides fixed-site laser vision correction services. In Portfolio Grader’s specific subcategories of Earnings Momentum and Earnings Revisions, LCAV also gets A’s. Shares of the stock have been trading at an exceptionally rapid pace, up 28209.6% from the week prior. For more information, get Portfolio Grader’s complete analysis of LCAV stock.

Chindex International, Inc. (CHDX) earns a B this week, jumping up from last week’s grade of C. Chindex provides healthcare services in China and internationally. The stock price has pushed upwards for the past 21 days, reaching $17.15. For more information, get Portfolio Grader’s complete analysis of CHDX stock.

Team Health Holdings, Inc. (TMH) boosts its rating from a C to a B this week. Team Health Holdings offers healthcare professionals outsourcing services. For more information, get Portfolio Grader’s complete analysis of TMH stock.

This week, Fresenius Medical Care AG & Co. KGaA Sponsored ADR (FMS) pushes up from a C to a B rating. Fresenius Medical Care offers kidney dialysis services and manufactures and distributes equipment and products used in the treatment of dialysis patients. At $36.57, the stock is above the 50-day moving average of $35.42. For more information, get Portfolio Grader’s complete analysis of FMS stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.