Meta has settled a big lawsuit.

Many US states said its apps hurt children's mental health.

The deal was announced Wednesday.

It ends a trial in California.

Meta will pay up to $18 billion.

It also adds new safety steps for young users on Instagram and Facebook.

Four states were in the settlement.

They are California, Colorado, Kentucky, and New Jersey.

It also ended a separate trial in Tennessee.

Tennessee Attorney General Jonathan Skrmetti said the deal gives "unprecedented protections" for kids.

He said it gives record-setting money for the state's Children's Digital Protection Fund.

Two states did not join the settlement.

New Mexico already won its own case against Meta.

A judge ordered the company to pay $567 million in August.

Florida's attorney general said the settlement was not tough enough on Meta.

Separately, hundreds of US school districts have sued social media companies.

They want money for costs related to children's mental health.

A Kentucky school district case settled before trial this summer.

In another first-of-its-kind case, a jury found Meta and YouTube liable for social media addiction.

The jury awarded $6 million in damages.

Both companies have appealed.