Research Reports: Systematic/Narrative ReviewExamining the Effectiveness of Year-Round School Calendars on Improving Educational Attainment Outcomes Within the Context of Advancement of Health Equity A Community Guide Systematic ReviewFinnie, Ramona K. C. DrPH; Peng, Yinan PhD, MPH; Hahn, Robert A. PhD, MPH; Johnson, Robert L. MD; Fielding, Jonathan E. MD, MPH, MBA; Truman, Benedict I. MD, MPH; Muntaner, Carles MD, PhD; Fullilove, Mindy T. MD, MS; Zhang, Xinzhi MD, PhD the Community Preventive Services Task ForceAuthor Information Community Guide Branch, Division of Public Health Information Dissemination, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia (Drs Finnie, Hahn, and Peng); Rutgers New Jersey Medical School, Newark, New Jersey (Dr Johnson); UCLA Fielding School of Public Health, Los Angeles, California (Dr Fielding); Center for HIV/AIDS, Viral Hepatitis, STD & TB Prevention (NCHHSTP), CDC, Atlanta, Georgia (Dr Truman); University of Toronto, Toronto, Ontario, Canada (Dr Muntaner); Columbia University, New York, New York (Dr Fullilove); and National Institute on Minority Health and Health Disparities, National Institutes of Health, Bethesda, Maryland (Dr Zhang). Names and affiliations of the Community Preventive Services Task Force members can be found at www.thecommunityguide.org/about/task-force-members.html. Correspondence: Robert A. Hahn, PhD, MPH, Community Guide Branch, Centers for Disease Control and Prevention, 1600 Clifton Rd, MS E-69, Atlanta, GA 30329 (firstname.lastname@example.org). The authors gratefully acknowledge the contributions of Krista H. Cole, Stacy A. Benton (from the Community Guide Branch, CDC), and Onnalee Gomez (from the Stephen B. Thacker CDC Library, Library Science Branch), who provided input on various stages of the review and the development of the manuscript. Kimberly Sarte (Joint Legislative Audit and Review Commission, Virginia) clarified issues on the Virginia study. The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of CDC. No author has any conflict of interest or financial disclosure. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (http://www.JPHMP.com). Journal of Public Health Management and Practice: November/December 2019 - Volume 25 - Issue 6 - p 590-594 doi: 10.1097/PHH.0000000000000860 Buy SDC Metrics Abstract Students may lose knowledge and skills achieved in the school year during the summer break, with losses greatest for students from low-income families. Community Guide systematic review methods were used to summarize evaluations (published 1965-2015) of the effectiveness of year-round school calendars (YRSCs) on academic achievement, a determinant of long-term health. In single-track YRSCs, all students participate in the same school calendar; summer breaks are replaced by short “intersessions” distributed evenly throughout the year. In multi-track YRSCs, cohorts of students follow separate calendar tracks, with breaks at different times throughout the year. An earlier systematic review reported modest gains with single-track calendars and no gains with multi-track calendars. Three studies reported positive and negative effects for single-track programs and potential harm with multi-track programs when low-income students were assigned poorly resourced tracks. Lack of clarity about the role of intersessions as simple school breaks or as additional schooling opportunities in YRSCs leaves the evidence on single-track programs insufficient. Evidence on multi-track YRSCs is also insufficient. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.