E-government services have emerged and expanded for the last decades. The digitalization of social services presents both an opportunity and a challenge to the aging population who are effectively digital immigrants. This study examined socioeconomic factors associated with e-government services awareness and usage among the aging population, with a focus on the comparison between baby boomers and older adults. Data came from the 2015 E-Government Services Usage Survey, a nationally representative survey in South Korea (N = 1,255). The results showed a cohort difference in e-government services usage as 69.3% of baby boomers vs. 34.9% of older adults. The logistic regression results also suggested differences in factors associated with e-government services awareness and levels of use by cohort. Household income was positively associated with awareness among baby boomers, while age was negatively associated with awareness among older adults. The findings imply that gerontological social workers need to advocate for senior citizens by urging the government to pay more attention to the issues of digital exclusion faced by the majority of the current cohort of older adults as well as subgroups of baby boomers - in particular those who are economically marginalized.