BOSTON (AP) – A lobbying group for senior citizens plans to appeal the dismissal of a lawsuit that seeks to force tobacco companies to pay at least $70 billion spent by Medicare on smoking-related illnesses.

The lawsuit filed last year by United Seniors Association Inc. was dismissed last week by a federal judge. The group filed notice Thursday that it will appeal.

United Seniors, based in Purcellville, Va., sued big tobacco companies, alleging they intentionally hid cigarettes’ addictive properties and should be held liable for Medicare’s expenditures since August 1999 to treat illnesses attributable to smoking.

The lawsuit named as defendants Richmond, Va.-based Philip Morris USA; R.J. Reynolds Tobacco Co., based in Winston-Salem, N.C.; Brown & Williamson Tobacco Corp., both individually and as the successors to the American Tobacco Co; Lorillard Tobacco Co., based in Greensboro, N.C.; and Liggett Group Inc., based in Mebane, N.C.

During a hearing in U.S. District Court in June, the companies asked Judge Richard G. Stearns to dismiss the lawsuit, saying they had not been found liable for the medical bills and United Seniors had no standing to bring the suit.

United Seniors claimed that under the Medicare as Secondary Payer law, they could seek to recover government losses on behalf of taxpayers.

In his order, Stearns cited a similar case in Florida, in which an appeals court said the plaintiff must prove a defendant’s responsibility to pay Medicare costs before trying to recover them under the Medicare as Secondary Payer law.

United Seniors estimates Medicare has spent an average of $10 billion per year over the past seven years to treat people suffering from tobacco-related illnesses.