​Why was Managed care developed?

Managed Care in general Developed in the United States as a response to spiralling healthcare costs and dysfunctional fragmented services, Medicaid and Medicare Managed care was adopted to prevent various types of Fraud, Waste and Abuse by both Consumers and providers.
Managed care  had been constantly in a progressive mode and constantly is constantly changing and adapting.

It seeks to cut the costs of health care while maintaining its quality, but many skeptics still question its merits as the evidence of it working as intended has yet to be proven.

The Jury is still out.

Due to its constantly changing nature, managed care is very complex and  intricate but all forms of it have one thing in common, simply stated:
An attempt to influence and modify the behavior and practice of patients and doctors as well as other health professionals towards cost effective care.