“Family language policy” (FLP) is the accepted term for the field of study of the explicit planning and practices concerning language within a family unit in a home. Previous research has shown that FLP aids in the bilingual acquisition of a child (DeCapua & Wintergerst 2009; Kayam & Hirsch 2014; King, Fogle, & Logan‐Terry 2008; Li 1999; Oh; Schwartz 2008). However, there has been little research providing answers to whether FLP has a direct influence on language maintenance in adulthood, especially whether they acquire and maintain a native or native-like accent in both languages. The purpose of this study is to determine if any and to what degree FLP influences the bilingual accent acquisition of Spanish/English heritage speakers in the United States. This is a qualitative case study performed through sociolinguistic interviews of three families containing now adult simultaneous bilinguals who learned Spanish and English throughout childhood. After obtaining information of each family’s FLP, each participant (n = 9) was asked to provide a speech sample in both English and Spanish (the heritage language). These samples were then rated by native speakers of English and Spanish respectively. Results suggest that the level of perceived foreign accent of the heritage language may be influenced by certain factors included in an individual FLP, as well as the speaker’s language confidence and individual differences including language aptitude.