South Carolina strengthened its charter school law last year, and a new national ranking reflects that improvement.

The National Alliance for Public Charter Schools, a nonprofit advocacy group, annually rates the strength of states’ charter school laws based on 20 factors. South Carolina jumped 13 spots to a No. 12 ranking among the 43 states with charter laws, according to a report released Tuesday.

Mary Carmichael is executive director of the Public Charter School Alliance of South Carolina, and she was among those who pushed hard for the legislative changes. She said she was excited to the see the higher ranking as well as the changes for charter schools statewide.

“The students are the ones who are truly benefiting as we transform the educational landscape in South Carolina,” she said.

Charter schools are public schools, but they are not governed by county school boards. They have separate boards to make decisions about funding, policy and curriculum. The state had 55 charter schools last year enrolling nearly 24,000 students.

The changes last year were among the most significant since the state passed its charter school law in 1996. Some of the more noteworthy ones include: allowing higher-education institutions to approve charter schools to open; permitting single-gender charter schools to exist; and letting charter school students participate in extracurricular or athletic activities at their neighborhood school if those aren’t offered at their charter school.

The alliance rates states based on whether their law has components that are part of its model law. South Carolina charter school advocates used the alliance’s model law as a guide last year.

Nina Rees, president of the national alliance, said states across the country are making their legislation stronger rather than diluting it, and that shows the charter movement is headed in the right direction.

“This is great progress for our sector and a great sign for things to come in the future,” she said.

Rees said the ranking doesn’t measure the quality of states’ charter schools but rather the quality of its law, which is necessary to have good charter schools.

The report is intended to be a guide for lawmakers looking for ways to improve their charter school laws. Carmichael said supporters were working with lawmakers on new proposals to provide facility money and to increase funding for schools in the statewide charter district.

Gov. Nikki Haley and others are talking about reforming the state’s education funding system, and “we want to be a part of that conversation,” Carmichael said.

State Superintendent of Education Mick Zais also supported the state’s new charter school law, and he said it’s encouraging to see national groups recognizing the state’s efforts “by raising South Carolina’s national rankings faster than almost every other state.”

“But there is more work to be done to improve the climate for public charter schools, specifically in the areas of equity funding, equal access to facilities, and access to transportation for public charter school students,” he said.

Reach Diette Courrégé Casey at @Diette on Twitter or 937-5546.