In an economy driven by technological innovation and a complex social landscape, schools can no longer count on traditional academic preparation to set children up for success later in life. The types of skills that will enable students to succeed in the 21st century--such as the ability to solve complex problems, transfer knowledge to new domains, and communicate with diverse audiences--are distinct from those routinely offered in K-12 education. To remedy these gaps, educators, school districts, and philanthropists have looked to a set of approaches that go by a variety of names (e.g., deeper learning, personalized learning, student-centered learning) but rest on a set of instructional approaches that allow students to express more agency over their learning and create space to apply what they learn to solve real-world problems. These 21st Century learning approaches are no longer only accessible to the most privileged students. This paper offers a first look at whether contemporary investments in 21st century learning are likely to pay dividends to students who have historically not benefited from these experiences, including students from low-income families and students entering school who have fallen behind. Drawing on a national study of schools implementing these practices and a deep look at two states (Colorado and Connecticut), the authors consider how academically disadvantaged students experience these learning environments and what factors contribute to their success with these approaches. They find that while 21st century learning is embraced by a surprisingly high number of schools serving historically underserved students, the uptake of these approaches does not always translate into better learning opportunities for those students. [This paper is part of a multiyear, multimethod study of 39 schools that participated in the Next Generation Learning Challenges (NGLC) Regional Funds for Breakthrough Schools initiative and the Next Generation Systems Initiative (NGSI), both supported by the Bill & Melinda Gates Foundation.]