Recommendations for adult pneumococcal vaccination in the U.S. were revised in 2022 after the introduction of 15- and 20-valent pneumococcal conjugate vaccines (PCV15 and PCV20) to call for routine PCV use among immunocompetent adults with risk conditions aged 19-64 years. The present study estimated the size of this newly recommended population. A retrospective cohort study was conducted using the Optum de-identified electronic health record (EHR) dataset. Patients who were active in the EHR between January 2016 and June 2021 and had ≥1 condition included in the current pneumococcal recommendation without an immunocompromising condition were included. Data were weighted to account for potential differences between the EHR and U.S. Data analyses were conducted in 2022. Of 45.6 million adults aged 19-64 years in the database, 12.5 million met inclusion criteria and had ≥1 qualifying condition, primarily smoking, with chronic lung disease/asthma and/or diabetes also common. After weighting, the U.S. population aged 19-64 years newly eligible for PCVs was approximately 56 million. Approximately one in four U.S. adults aged <65 years is now recommended to receive PCV15 or PCV20, which highlights the need for providers to assess vaccination status, administer the vaccine, or refer patients as appropriate, as well as the need for tools to facilitate patient identification and vaccination.