The grants, Mominey said, are available for all transferring 10th-, 11th-, and 12th-grade students who qualify for admission and enroll at one of the schools in the fall.
The grants will help defray the cost of Catholic high schools, where annual tuition and fees range from $6,500 to $7,000.
Mominey said other dioceses had found that "sometimes, that $1,000 makes the difference for families."
Students may also be eligible for scholarships based on financial need.
Mominey said there was no limit on the number of grants available.
"We've made a commitment to accept as many students as are qualified," Mominey said.
Admission is limited to students who have successfully completed their academic requirements. The schools also review disciplinary records before permitting students to enroll.
The transfer-advantage program for the 2014-15 year will run into October and will be open to students who have enrolled at other schools, but decide after classes begin that a Catholic school will be a better option.
The foundation, which took over management of the Catholic high schools in September 2012, aims to boost enrollment 2 percent above the 13,794 students in the academic year just ended.
The foundation also has launched a campaign to publicize the high schools with radio spots and transit ads.
Information about the grants program is available at a new website, www.transferadvantage.org.