It was about ten years ago congress passed a law to make mental health insurance coverage equivalent to their physical health coverage.

From google AI:

The Mental Health Parity and Addiction Equity Act (MHPAEA) is a federal law that requires health insurance plans to provide equal coverage for mental health and substance use disorder (MH/SUD) benefits as they do for medical and surgical benefits. The law was enacted in 2008 and aims to ensure that people seeking mental health care do not face more barriers to treatment than those seeking medical care