This paper takes up the practical question of whether sufficient private school seats would be available for a voucher initiative to get off the ground in Massachusetts. To collect the necessary data, Pioneer Institute designed and conducted a survey of the 524 private, K-12 non-special education schools in Massachusetts. One hundred ninety-four schools serving a total of 50,435 K-12 students responded to the survey, representing 37 percent of all K-12 non-special education private schools in Massachusetts and approximately 43 percent of private school population.