Cigna on Thursday finalized its $67 billion merger with Express Scripts, a landmark deal that promises to transform the healthcare system and usher in a new era of competition between hybrids of insurers and pharmacy benefit managers.

“Together, we are establishing a blueprint for personalized, whole person health care, further enhancing our ability to put the customer at the center of all we do by creating a flexible, open and connected model that improves affordability, choice and predictability,” David Cordani, Cigna’s chief executive officer, said in a statement.