The Department of Health and Human Services on Wednesday finalized a key health reform rule that most notably expands mental health and substance abuse benefits to 62 million Americans.

The rule, to take effect next January, outlines standards for a core package of benefits—called essential health benefits—that health insurance issuers must cover both inside and outside the health insurance exchanges. Through its standards for essential health benefits, the final rule expands coverage of mental health and substance use disorder services, including behavioral health treatment, for millions of Americans.

The agency said the policies outlined "will give consumers a consistent way to compare and enroll in health coverage in the individual and small group markets, while giving states and insurers more flexibility and freedom to implement the Affordable Care Act."