WASHINGTON D.C. — U.S. health regulators on Thursday approved Medicare coverage for lung cancer screening by low-dose CT, the first time the government health insurance program for the elderly and disabled will pay for such a program of early detection in an effort to save lives.

The decision applies to Medicare beneficiaries aged 55-77 who are current smokers or who quit within the last 15 years, and who racked up at least 30 “pack years.” The latter is possible if they smoked one pack a day for 30 years, for instance, two packs a day for 15 or three packs a day for a decade.

The coverage is effective immediately, the Centers for Medicare and Medicaid Services announced, and applies nationwide.

In a statement, CMS chief medical officer Dr. Patrick Conway called the decision to pay for a once-a-year screening “an important new Medicare preventive benefit since lung cancer is the third most common cancer and the leading cause of cancer deaths in the United States.”

The usually-incurable disease will kill about 158,000 people in the U.S. this year, according to the American Cancer Society; 221,200 cases will be diagnosed.