Human immunodeficiency virus (HIV) partner services are an essential component of comprehensive HIV prevention and care. We examined factors associated with partner notification, HIV testing, and HIV positivity among partners of HIV-diagnosed persons (index persons) contacted by Centers for Disease Control and Prevention (CDC)–funded state and local health departments.

We analyzed partner service data submitted to the CDC by 61 state and local health departments from 2013 to 2017. Using multivariate Poisson regression—adjusted for clustering effects among partners reported by a common index person—we assessed associations between 3 outcomes of interest (partner notification, HIV testing, and HIV positivity) and the demographic characteristics, risk behaviors, geographic region, and service year of index persons and their partners.

A total of 51,368 sexual and/or needle-sharing partners were matched with 33,524 index persons. Of notifiable partners, 97.2% were notified of their potential HIV exposure, and 52.3% were tested for HIV. Among 21,842 notified and tested partners, 23.8% were newly diagnosed with an HIV infection. Partner notification, HIV testing, and HIV positivity were associated with both partner and index person characteristics (individually and interactively), geographic region, and year of service.

Partner service programs provided through CDC-funded health departments were effective in both partner notification and identification of undiagnosed HIV infection among partners. However, HIV testing rate among notified partners remained low. Implementing strategies to address gaps in HIV testing can contribute toward ending the HIV epidemic in the United States.