Adipose tissue is rapidly expanding early in life. Identifying the queues facilitating this process will advance our understanding of metabolically healthy obesity. Single-cell RNA sequencing revealed compositional differences between pre-wean and adult murine subcutaneous adipose tissue. We identify a dipeptidyl peptidase-4 (Dpp4) positive precursor population in pre-wean mice residing at the reticular interstitium of subcutaneous adipose tissue expressing insulin growth factor 2 (Igf2). We show that IGF2 drives proliferation rather than differentiation in these cells. Moreover, loss of Igf2 in Dpp4+ progenitor cells promotes adipogenesis. We show that expression of Igf2 at a limited timeframe during development promotes preadipocyte expansion.