Highmark, stoking membership growth, wants to buy all of Gateway Health

Highmark Inc. continues to expand membership, this time with agreement to buy the half of Medicaid managed care insurer Gateway Health that Highmark doesn’t already own. Highmark, a health insurer and hospital network operator, is seeking state regulatory approval to acquire Downtown-based Gateway Health from Trinity Health of Livonia, Mich. Highmark has owned 50% of Gateway since the founding of the nonprofit insurer in 1992.