Although 20 states have adopted Next Generation Science Standards (NGSS), 24 other states have developed their own K-12 science standards based on the same National Research Council (NRC) Framework. Understanding what influences content standards developers, realizing the supports and impediments to implementation they foresee, and knowing their rationales for implementing standards is important because these elements potentially affect their contributions and may have repercussions throughout the educational system. Forty-four developers of one state's NRC Framework-based science standards indicated the degree to which they were affected by educational system influencers (e.g., accountability), by their beliefs, values, and experiences, and by consideration of others (e.g., administrators). Developers described rationales they think others will have for supporting and being concerned about new science standards and their personal rationales for supporting new science standards. Among results, developers were substantially influenced by considerations of educators interpreting new standards and designing curriculum.Developers' experiences with teaching science and implementing standards weighed considerably more on their minds than considerations about administrators or colleagues. Developers believe new science standards possess tremendous intrinsic value but also believe others will primarily leverage rationales that new science standards are connected to state assessments and accountability as means to obtain teacher buy-in. K E Y W O R D S content standards, developers, NGSS, science standards,