Teachers who spend their own money on classroom supplies — most of the nation’s nearly 4 million K-12 teachers — would be eligible for a permanent tax credit of up to $250 annually for unreimbursed expenses, under a bill passed by the House Ways and Means committee on Thursday.

The tax credit, which would be adjusted with inflation, would be available to any K-12 teacher, instructor, counselor, principal, or aide who purchases supplies, equipment or software to be used in the classroom. The credit could also be applied to the cost of professional development.

Teachers had already been eligible for a $250 tax credit but that provision had expired in January and had not been indexed for inflation.

“This tax deduction is timely, permanent, and will go a long way toward making sure educators continue to provide what students need to succeed,” said Lily Eskelsen García, president of the National Education Association, the nation’s largest teachers union.

According to a survey by the National School Supply and Equipment Association, 99.5 percent of all public school teachers spend their own money on classroom supplies and equipment. During the 2012-13 school year, educators spent a total of $1.6 billion from their own pockets on supplies and materials, the survey found. That means the average teacher spent $485 and 10 percent spent at least $1,000.

“Public schools are still feeling the impact of the growing number of homeless students and of students living in poverty,” Eskelsen Garcia said. “As a result, too often educators across the country sacrifice and reach into their own pockets to buy supplies and materials that help meet students’ basic needs.”

According to new federal data, the number of homeless children in public schools has doubled since before the recession, reaching a record national total of 1.36 million in the 2013-2014 school year.

In addition, schools strapped for funds are increasingly cutting back on the kinds of classroom supplies that were provided without question a generation ago.

The legislation would add $2.5 billion to the budget deficit over the next decade. It was one of five tax bills that were passed by Republicans on the committee without a single Democratic vote. The other cuts included tax breaks for restaurants, multinational corporations and other businesses. Combined, they totaled $412 billion, angering Democrats who said they added to the deficit.

The bills now move to the full House for a vote.