Pneumococcal vaccine uptake targets set by Healthy People 2020 were not met by 2019 among vulnerable United States populations, yet research suggests progress can be made in primary care settings. This study assessed factors associated with having gotten a pneumococcal vaccine among vulnerable adults aged 50 and older. This study used the 2018 Medical Expenditure Panel Survey nationally representative dataset. Eligible individuals were aged 50–64 with an ‘at risk’ health condition or ≥65 years and had a primary care provider as their usual source of care (N = 3,760). Binary logistic regression was used to test factors (identified from literature) for a significant association with getting the pneumococcal vaccine. Factors with significant associations were entered into an adjusted multivariable logistic regression model to generate the odds of endorsing a factor given that the respondent got the vaccine. Collinearity among variables was examined with an unacceptable threshold of 0.8 correlation. A significance threshold of 0.05 was used. Those who got the pneumococcal vaccine had 16.7 (p < 0.001), 16.0 (p < 0.001) and 11.0 times (p < 0.001) higher odds of having also gotten the influenza vaccine, the herpes zoster vaccine and a colonoscopy respectively. They had 3.86 times (p = 0.009) higher odds of having diabetes mellitus, 0.036 times (p = 0.019) higher odds of having visited their doctors three times in 2018 and 8.4 times (p = 0.009) higher odds of having seen their doctor within the last year. Concordance statistic for model fit was 0.936. There was a negative association between pneumococcal vaccination and going to three doctor office visits in 2018 vs only once. The strongest positive associations were found between pneumococcal vaccination and getting the herpes zoster vaccine, influenza vaccine and getting a colonoscopy. These results suggest that those who choose to get the pneumococcal vaccine may have higher odds of also getting other vaccines or specific preventative screenings.