Executive Summary The National HIV Surveillance System (NHSS) is the mechanism through which the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP), Division of HIV/AIDS Prevention (DHAP), HIV Incidence and Case Surveillance Branch (HICSB) monitors trends in HIV infection diagnoses in the United States. Data collected on reported HIV cases are also used to estimate the prevalence and incidence of HIV infections, progression of disease after diagnosis, and receipt of care (based on laboratory tests after diagnosis). NHSS data guide public health action at federal, state, and local levels and help public health officials develop, implement, and evaluate HIV prevention programs (including efforts to prevent disease progression after diagnosis). Information on HIV infection and disease progression can be used to determine where HIV prevention services are most needed and ensure that persons living with HIV infection receive appropriate care. CDC-funded health departments report HIV case surveillance data to NHSS. The CDC National HIV Prevention Program Monitoring and Evaluation (NHM&E) system provides data about CDC-funded HIV testing and other prevention activities conducted by CDC-funded health departments and community-based organizations. HIV testing is one of the DHAP core HIV prevention strategies. NHM&E testing data are used at federal, state and local levels to inform HIV prevention policy, program decision-making, and program monitoring and evaluation activities. Tracking persons newly diagnosed with HIV infection and their timely access to HIV medical care is important for CDC-funded HIV prevention programs. This supplement is an expansion of activities under FOA CDC-RFA-PS13-1302. The purpose of the project is to improve the quality and completeness of CDC-funded HIV testing data through the sharing of data between the HIV surveillance program and the HIV prevention program at each health department. Health departments will implement strategies for sharing HIV testing and HIV case surveillance data between these two programs to improve the accuracy of data on new and pre-existing HIV diagnoses and linkage to HIV medical care among persons newly diagnosed with HIV infection.