This week, the ratings of 6 Health Care Providers & Services stocks on Portfolio Grader are down. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Centene Corporation (CNC) earns a D this week, moving down from last week’s grade of C. Centene Corporation is a multi-line healthcare enterprise engaged in Medicaid managed care and other specialty services. For more information, get Portfolio Grader’s complete analysis of CNC stock.

This week, CorVel Corporation (CRVL) drops from a D to a F rating. CorVel Corporation provides managed care services in the workers’ compensation, accident and health, and auto insurance markets across the United States. For more information, get Portfolio Grader’s complete analysis of CRVL stock.

This week, Premier Inc. Class A’s (PINC) rating worsens to a F from the company’s D rating a week ago. The company also gets F’s in operating margin growth and earnings momentum. For more information, get Portfolio Grader’s complete analysis of PINC stock.

Aceto Corporation’s (ACET) rating weakens this week, dropping to a F versus last week’s D. Aceto Corporation is engaged in the sourcing, quality assurance, marketing, and distribution of pharmaceuticals and other chemical-based products in the health and crop production sectors. The company also gets F’s in earnings momentum. For more information, get Portfolio Grader’s complete analysis of ACET stock.

This is a rough week for iKang Healthcare Group, Inc. Sponsored ADR Class A (KANG). The company’s rating falls to F from the previous week’s D. The company also gets F’s in operating margin growth and earnings momentum. For more information, get Portfolio Grader’s complete analysis of KANG stock.

Concord Medical Services Holding Ltd. ADR (CCM) slips from a C to a D this week. Concord Medical Services Holding Ltd. ADR operates a network of radiotherapy and diagnostic imaging centers in the People’’s Republic of China. The company also gets F’s in sales growth, operating margin growth, and earnings growth. For more information, get Portfolio Grader’s complete analysis of CCM 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.