The Centers for Disease Control and Prevention (CDC), the federal government's lead public health agency, has identified teen pregnancy as a major public health issue because of its high cost for families of teenage parents and society more broadly. In addition, teen pregnancy disproportionately affects certain minority communities and selected states and territories. The teen birth rate has been in decline; however, given the consequences associated with teen births, Congress has continued to authorize, and the executive branch has administered, programs to delay sexual activity and prevent pregnancies among teenagers. Four current programs have an exclusive focus on teenage pregnancy prevention education: the Teen Pregnancy Prevention (TPP) program, which is authorized under appropriations law; the Personal Responsibility Education Program (PREP), which is authorized under Title V of the Social Security Act; the Sexual Risk Avoidance Education program, which is authorized under Title V of the Social Security Act (and formerly known as the Title V Abstinence Education Grant program); and the Sexual Risk Avoidance Education program, which is authorized under appropriations law. This report will refer to the latter two programs as the Title V Sexual Risk Avoidance Education program and the Sexual Risk Avoidance Education program, respectively, to avoid confusion. The four programs are administered by the U.S. Department of Health and Human Services (HHS). This report begins with a brief discussion of recent developments in funding for the four teen pregnancy prevention programs. It then provides background on the role of Congress and the executive branch in preventing teen pregnancy. The remainder of the report focuses on the four programs, examining the types of grants they provide as well as related funding, requirements, and research activities. Table A-1 in Appendix A summarizes key programmatic information and allows for comparisons across the programs. Table A-2 in Appendix A describes the changes made by the Bipartisan Budget Act of 2018 (BBA of 2018, P.L. 115-123 ), enacted on February 9, 2018, to Section 510 of the Social Security Act. The BBA of 2018 renamed the Title V Abstinence Education Grant program as the Title V Sexual Risk Avoidance Education program and made other programmatic changes, retroactively effective October 1, 2017. Appendix B includes a table that indicates whether the states and territories, or entities within those jurisdictions, receive funding under each of the four programs. This report accompanies CRS Report R45184, Teen Birth Trends: In Brief . The federal government has long played a role in educating teens and the public generally about preventing pregnancy and sexually transmitted infections (STIs). This has involved public awareness campaigns; providing public health services, including information and access to contraceptives; publishing materials about STIs; and funding organizations to provide sexual education. The federal approach to teen pregnancy prevention has often reflected prevailing public views about sexuality and the role that the federal government should play in the private lives of its citizens. Since the early 1980s, the federal government has supported programs that have an exclusive focus on preventing teen pregnancy. Discussion about these programs has often focused on the type of approaches to pregnancy prevention they should take. Some policymakers and other stakeholders in the teen pregnancy prevention field have contended that teens should not engage in sex before marriage to avoid unplanned pregnancies and protect against STIs. Further, they support the idea that teenagers need to hear a single, unambiguous message that sex outside of marriage is harmful to their physical and emotional health. This approach is sometimes referred to as "abstinence-only," and more recently as "sexual risk avoidance." Other stakeholders have prioritized an approach that provides broad information to teenagers to help them make informed decisions about whether to engage in sex, and about using contraceptives if they do. They contend that such an approach allows young people to make choices regarding abstinence, gives them the information they need to set relationship limits and resist peer pressure, and provides them with information on the use of contraceptives and the prevention of STIs. Congress has authorized and provided funding for programs that take one or both of these approaches to preventing teen pregnancy. Of the current programs, the Title V Sexual Risk Avoidance Education and the Sexual Risk Avoidance Education programs focus exclusively on abstaining from premarital sex. The PREP program requires most grantees to place "substantial emphasis on both abstinence and contraception for the prevention of pregnancy among youth and sexually transmitted infections." The TPP program does not necessarily focus on any one approach, and some grantees use multiple program models to meet the various needs of youth. For example, a TPP program grantee in South Carolina uses an evidence-based model that provides abstinence-only education and other evidence-based models that have broader approaches. The general public appears to support educating teenagers about both abstinence and contraception. A nationally representative telephone survey conducted in 2017 for Power to Decide, an organization focused on preventing unplanned pregnancy, found that about 8 out of 10 adults believe teens should receive more information about abstinence and birth control and protection from sexually transmitted infections. Two of the current teen pregnancy programs, TPP and PREP, reflect government-wide efforts beginning in the George W. Bush Administration and extending into the Obama Administration to expand social programs that work and eliminate those that do not. The two programs use a "tiered evidence" approach: some grantees employ teen pregnancy prevention models that are effective based on rigorous evaluation while other grantees develop and rigorously evaluate new or innovative approaches to reducing teen pregnancy. HHS has identified which teen pregnancy prevention program models meet selected criteria for being considered "evidence-based." Multiple HHS offices worked together to establish the Teen Pregnancy Prevention (TPP) Evidence Review process following enactment of the FY2010 omnibus appropriations law ( P.L. 111-117 ). P.L. 111-117 also authorized the TPP program and required it to use models that are proven effective through rigorous evaluation in reducing teen pregnancy and related outcomes. Despite the connection to the TPP program, the review is intended to more broadly inform the teen pregnancy prevention field. The TPP Evidence Review seeks to identify which teen pregnancy prevention models have been shown to be effective based on studies from the past 20 years. The review team prioritizes studies of programs based on whether they include youth ages 19 and younger and are intended to address teen pregnancy outcomes through some combination of educational, skill-building, or psycho-social interventions. The first review covered research released from 1989 through January 2010. Subsequent reviews have since been conducted on an annual or biannual basis to incorporate new research, including newly available evidence for programs that were previously reviewed. These studies must have one statistically significant impact on at least one of five areas: (1) sexual activity, (2) number of sexual partners, (3) contraceptive use, (4) STIs or HIV, and (5) pregnancies. In addition, the studies must examine impacts of programs using randomized controlled trials (RCTs) and quasi-experimental impact study designs. For the studies that meet these initial criteria, reviewers assign each one a rating of high, moderate, or low quality based on whether it uses RCTs and quasi-experimental design, has relatively low attrition, controls for differences between the treatment and comparison groups, and meets certain other criteria. After its latest round of studies, the TPP Evidence Review includes 41 evidence-based program models. Evidence-based teen pregnancy prevention programs are varied and approach the problem from different frameworks. HHS categorizes the evidence-based models based on certain key features. For example, three of the models use an abstinence-only approach and some of the models incorporate information about abstinence. Other models focus on sexual health education, youth development, clinic-based services, and/or youth with certain histories (e.g., youth who are incarcerated). Programs differ based on their outcomes, settings (e.g., schools, clinics, homes, afterschool programs), session length and duration over time, and target population (e.g., males, females, African American youth, Hispanic youth, low-income youth, rural youth). HHS has taken additional steps to develop research on teen pregnancy prevention interventions. These efforts have been funded through annual appropriations of approximately $4.5 million to $6.8 million in each of FY2011 through FY2018 for Section 241 of the Public Health Services Act (PHSA). Section 241 provides authority for HHS to conduct evaluations of the implementation and effectiveness of public health programs. The funding has been used to support federal evaluations on teen pregnancy, including evaluation of TPP grantees; technical assistance about using rigorous program evaluation for TPP program grantees and unrelated grantees funded through the CDC; the TPP Evidence Review; and measuring performance data for the TPP program and Pregnancy Assistance Fund (PAF) grantees. The PAF provides competitive funding to state and tribal agencies to support pregnant and parenting teens and adults in school-based and community-based settings. The Consolidated Appropriations Act, FY2010 ( P.L. 111-117 ) established and provided annual funding for the Teen Pregnancy Prevention (TPP) program. The TPP program has been funded via the appropriations process in subsequent years, including through FY2018. Funding has ranged from approximately $98 million to $110 million annually. The program primarily provides funds to public and private entities for evidence-based or promising programs that reduce teen pregnancy, including those that focus on sexual risk avoidance and/or use of contraceptives. However, HHS is in the process of discontinuing funding for the current cohort of TPP program grantees. See "Recent Developments" at the beginning of this report for further detail about the status of current funding. Generally, the appropriations laws have specified that no more than 10% of TPP funding is for training and technical assistance, outreach, and other program support.