Meta has settled a big lawsuit with many US states.

The states said Meta's apps hurt children's mental health.

The deal was announced on Wednesday.

It ends a trial in California.

Meta will pay up to $18 billion.

It will also add new safety rules for young users on Instagram and Facebook.

Four states were part of the lawsuit.

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

The deal also ended a separate trial in Tennessee.

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

He said it also gives a record amount of money to the state's Children's Digital Protection Fund.

Two states did not join the deal.

New Mexico had already won its own case against Meta.

A judge ordered Meta to pay $567 million in August.

Florida's attorney general said the deal was not hard enough on Meta.

Separately, many US school districts have sued social media companies.

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

A case in a Kentucky school district settled before trial this summer.

In another first-of-its-kind case, a jury said Meta and YouTube were responsible for social media addiction.

The jury awarded $6 million in damages.

Both companies have appealed.