As Island students settle into a new school year, school business administrator Amy Tierney said she will spend the fall the way she always does: supporting her staff and district accountants as they put together reports for the state.

“It’s huge, and we have to do five of them because we have five districts,” she said. High school accountant Mark Friedman does most of the high school’s report, and accountant Lynn Rebello does most of the up-Island report.

“And I do Edgartown, Tisbury and Oak Bluffs myself,” Ms. Tierney said.

The work spills into her evenings and weekends until Thanksgiving.

School budgets together add up to about $50 million a year, a total that surpasses the budget of every town on the Island. The regional high school alone has an annual budget of about $20 million.

“Those two districts are a unique municipality,” she said of the high school, which is paid for by all six towns, and the up-Island regional school district, which includes the three up-Island towns and two schools. “We run all of the cash and all of the payroll and pay all the bills, so we’re really running that municipality,” she said.

Before taking the school business job in 2002, she was town accountant in Chilmark. She has also been assistant to the town accountant in Tisbury and has served on Tisbury’s finance committee and school committee.

This year, she was elected by about 350 of her peers at other schools as president of the Massachusetts Association of School Business Officials (MASBO). She said involvement with the group has allowed her to travel around the country to see how other school systems are funded. It has also brought her together with school business administrators from other countries.

“When we get together, they’re like another family to me,” she said. “They’re all people like me that do what I do and understand the craziness of this type of a job.”

Each month she attends dozens of school committee, budget and facilities meetings. She carries a small case loaded with 16 flash drives to track among other things, large building and facilities projects being put out to bid. If she can’t make a meeting, it’s not unusual for committee members to declare progress impossible without her presence and guidance.

Despite their five separate and sovereign districts, each containing a different combination of towns and schools, Island public schools share special education funds through the superintendency union. Transportation services are shared as well, with a budget that tops $1.5 million. Then there are the 20 or more scholarship funds Ms. Tierney’s office manages.

“At Class Night, we gave away almost $2 million this year,” she said. “All that money comes through different trust funds through the families and the earnings on those trusts.”

In her office, a photograph of her daughter, Andrea, taken in 1999, hangs on the wall. It shows Andrea sitting at her third grade desk at the Tisbury school, glasses sliding down her nose, pencil in hand.

“This to me is the purpose,” Ms. Tierney said. “It’s so important.”