BACKGROUND: Standardization in production is common in multientity chain organizations. Although chains are prominent in the nursing home sector, standardization in care has not been studied. One way nursing home chains may standardize is by controlling the level and mix of staffing in member homes. OBJECTIVES: To examine the extent to which standardization occurred in staffing, its relative presence across different types of chains, and whether facilities became more standardized following acquisition by a chain. RESEARCH DESIGN: We estimated predictors of the difference between facility and chain staffing using Generalized Estimating Equations with 2000-2010 data. SUBJECTS: This study included nursing homes nationally, excluding hospital-based homes and homes in Alaska, Hawaii, and the District of Columbia. MEASURES: Chain ownership was coded from text identifying chain names. Two nurse staffing measures were used: staff hours per resident day and staff mix. RESULTS: Very large for-profit chain nursing homes and large nonprofits had less variation in staff hours per resident day (P<0.001) but greater variation in staffing mix (P<0.001) compared with the chain average nationally. Large for-profit chains and medium nonprofit chains had greater dispersion on staff hours per resident day (P<0.001), while large nonprofit chains had greater dispersion in staffing mix (P<0.001). The difference between facility and chain staffing decreased over time. CONCLUSIONS: The largest chains (for-profit and nonprofit) had less staffing variation compared with national standards, suggesting they were best at implementing corporate practices. Following ownership changes, staffing converged towards chain averages over time, suggesting standardization takes time to implement.