SALEM — More than 10,000 children have been added to the state health plan under a new law aimed at expanding health insurance coverage to nearly every child in Oregon, officials said Tuesday.

Cathy Kaufmann, manager of the program, said the sign-ups since the law took effect Oct. 1 put Oregon on track to cover nearly 95 percent of its children. The state hopes to add an additional 70,000 children by the end of next year under the “Healthy Kids” program that was passed by the 2009 Legislature.

“This is going to make a big difference in the lives of thousands of kids around Oregon,” Kaufmann said of the expansion effort.

In October, families with incomes up to 200 percent of the poverty level, or about $44,000 for a family of four, were made eligible to enroll their children in the Oregon Health Plan.

The next step comes in January, when the state will begin subsidizing premiums on a sliding scale for children in families that make up to 300 percent of the poverty level, or $66,150 for a family of four.

Kaufmann said families can begin submitting applications now to receive that coverage.

To pay for the expanded coverage, the Democrat-led Legislature imposed a 1 percent tax on health insurance premiums, and allowed insurers to pass on the tax to employers and customers. That provision won approval over the opposition of Republicans.

Gov. Ted Kulongoski and Democratic lawmakers touted Oregon’s expansion as the biggest passed by a state legislature this year — with Montana coming in second by extending coverage to 30,000 more children.

Kaufmann said that while lawmakers in Washington, D.C., are continuing to debate national health care reform, Oregon has moved ahead with a program step to help more families obtain health coverage for children amid a struggling economy.

“As Oregonians, we ought to feel proud that we are taking this aggressive step,” she said.