This week, 4 Health Care Providers & Services stocks are improving their overall rating on Portfolio Grader. Each of these rates an “A” (“strong buy”) or “B” overall (“buy”).

Express Scripts Holding Company (ESRX) gets a higher grade this week, advancing from a C last week to a B. Express Scripts Holding Company is a full service pharmacy benefit management and specialty managed care company serving clients throughout North America. The company also gets A’s in free cash flow. For more information, get Portfolio Grader’s complete analysis of ESRX stock.

Amedisys, Inc. (AMED) improves from a B to a A rating this week. Amedisys, Inc. provides home health care and hospice services in the United States. For more information, get Portfolio Grader’s complete analysis of AMED stock.

Aceto Corporation (ACET) boosts its rating from a B to a A this week. 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 A’s in operating margin growth, earnings growth, earnings revisions, earnings momentum, and free cash flow. For more information, get Portfolio Grader’s complete analysis of ACET stock.

This is a strong week for Triple-S Management Corporation Class B (GTS). The company’s rating climbs to B from the previous week’s C. Triple-S Management Corporation Class B is an independent licensee of the Blue Cross Blue Shield Association. The company also gets A’s in sales growth, operating margin growth, and free cash flow. For more information, get Portfolio Grader’s complete analysis of GTS 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.