A single Philadelphia school ranked among the top 500 best educational institutions in the country, according to the annual US News & World Report rankings released Tuesday by Philly.com.

It is the Julia R. Masterman High School, whose Advance Placement program for college preparation and its excellent student performance in math and reading helped it to rank 51st in the national ranking, five places below her last Ranking last year.

A research by US News & World Report, in partnership with the social research organization RTI International, was conducted on a total of 20,487 public schools in the country, which at least met the requirements of high enrollment rates in students in grades 12, through 2014 and 2015.

According to the portal, the process for determining which are the best schools in the United States - classified in three categories using the Olympic system of “gold, silver and bronze” medals - includes four stages in which they evaluate both student performance in state tests as well as success rates in terms of graduation and enrollment in academic programs designed to advise and prepare students on their way to college.

In that sense, the Julia R. Masterman High School registered an index of 92.9 percent in preparation of its students for the university life; 92 percent of its student body approved the Advance Placement program and all the students show high standards of mathematical and reading skills.

Other aspects evaluated are related to the academic performance of the children considered as "disadvantaged" – some of them being Hispanic and underserved - compared to the state average.

This way, the Julia R. Masterman High School also ranked in the first place in Pennsylvania.

Among the 17 schools in the Philadelphia School District that were ranked nation wide are the Central High School (silver medal, ranked 18 in the state, 791 in the country), Academy at Palumbo (silver medal, 31st in the state, and 1197 in the country), the Creative and Performing Arts (silver medal, ranked 52 in the state, and 1725 in the country), Carver High School (silver medal, 64th place in the state, 2071 nationally) and the Girardd Academic Music Program (silver medal, ranked 64 at the state level and 2097 at the national level).

Two Philadelphia charter schools also appeared in a category for this type of educational establishment: the MAST Community Charter School, which ranked 197th and Mastery Charter School-Thomas, ranked 264th.

The three best public schools in the United States are located in Arizona: Basis Scottsdale, Basis Tucson North and Basis Oro Valley, in the first, second and third place respectively.