This study is a multiple case study of two Korean immigrant families: a multigenerational household and a nuclear household. I examined biliteracy language practices, their perceptions on gaining bi/multiliteracy, and intergenerational nurturing and support for the younger generations’ biliteracy development in their home contexts. This study was framed by sociocultural theory with a critical perspective (Street, 1993; Vygotsky, 2012), multiliteracies (Cope & Kalantzis, 2000, 2009), the continua of biliteracy (Hornberger, 2003; Hornberger & Skilton-Sylvester, 2000), and translanguaging (García, 2009; García & Li, 2014). The findings indicate that each family demonstrated unique and dynamic language practices along with the complex interplay of language ideologies, perceptions, past experiences, and power relations. Accordingly, each family’s support for their child’s biliteracy development varied. In the three-generation household, biliteracy is the norm for their daily language practice; however, the family’s monolingual ideology and understanding of bilingualism resulted in fewer intergenerational interactions to support the younger generation’s biliteracy development. The nuclear family, despite fewer opportunities to interact with the grandparents, demonstrated multilingual ideology and flexible bilingualism which resulted in the dynamic language practices among the parents and child. Both families have shown the complex interplay of factors around the use of English and Korean in the home context as well as diverse ways of supporting the younger generations’ biliteracy development. The implications from this study call attention to the necessity for meaningful support for multicultural and multilingual families’ maintenance of cultural and linguistic heritage in the family, school, and community with appropriate government policy enactment.