You must mean this subtraction below, from VA.tax.gov
It's very clear that employees of public colleges or community colleges qualify but doe snot specifically address lower grade public schools. Who shows as the employer on your W-2?
"Federal and State Employees
Federal and state employees whose total salary from all employment during the taxable year is $15,000 or less may subtract up to $15,000 of the salary received from a federal or state government job. Virginia employees working in universities, colleges and community colleges who are eligible for the subtraction include, but are not limited to: Virginia employees of state-supported institutions of higher education in the Commonwealth, and employees of publicly supported comprehensive community colleges. Federal employees who are not eligible for the subtraction include but are not limited to the following: Members of the active or reserve components of Army, Navy, Air Force, or Marines, National Guard of Virginia, any other state, or District of Columbia. Additionally, local government employees and United States Postal Service employees are not eligible for the subtraction. If the total salaries reported exceed $15,000, you may not claim the subtraction. For example, an individual who earned $10,000 in a federal or state government job and $15,000 in a private sector job during the taxable year 2005 would not be eligible for the subtraction. Unearned income, such as pensions and annuities, is not considered in determining eligibility for the subtraction. For example, an individual who received federal or state government wages of $14,000 and pension income of $35,000 during the taxable year would be eligible to claim the subtraction. Code of Virginia Section 58.1-322 [C] [24]"
