MADISON, Wis. -- Democratic lawmakers said they'll introduce a bill to improve insurance coverage for the mentally ill and drug addicts.

The measure wouldn't mandate coverage for mental health and substance abuse problems. It would, however, require all group health plans that offer such coverage to provide it at what's known as parity. Essentially, mental illness and substance abuse coverage couldn't be more restrictive or expensive than the plan's medical and surgical coverage.

Bill sponsors said a person is currently capped at about $6,300 in services and that figure has not been raised in 24 years.

State Sen. Dave Hansen, D-Green Bay, one of the bill's supporters, said the measure will help people who work for smaller employers afford insurance.

"I am co-sponsoring this legislation because I believe requiring equal treatment for mental and physical disorders is in the best interest of employees and employers in this state," Hansen said.

Federal law mandates mental health and substance abuse parity for health plans offered by employers with 51 workers or more.