Adopting management accounting systems are important events in the life of young and growing companies. Using a sample of 78 startup companies, we document cross-sectional differences in the adoption of operating budgets as well as seven other management accounting systems. We find that our proxies for agency costs, perceived benefits and costs, complexity of the firm, and culture explain cross-sectional differences in time-to-adoption of budgets. In particular, the presence of venture capital, CEO experience, firm size, and the culture of the organization are associated with this adoption decision. We further investigate the effect of hiring a financial manager as an endogenous variable. In the first stage of a two-stage model, we find that CEO total experience, the presence of venture capital funds, culture, and firm size are associated with cross-sectional variation in this hiring decision. When treating this decision as endogenous, time to hiring a financial manager is unrelated to operating budget adoption. The paper also examines the association between the time-to-adoption of operating budgets and company performance. We find a significant increase in the size of the company around the adoption of operating budgets; moreover faster adoption of operating budgets is associated with faster growing companies. We extend the findings to additional management accounting systems including: cash budgets, variance analysis, operating expense approval policies, capital expenditure approval policies, product profitability, customer profitability, and customer acquisition costs. The influence of industry choice (biotechnology, information technology, or non-tech) is examined in each stage of the research.