As payers move towards bundled payments, understanding sources of payment variation—including use of medical consultants—is important. In an observational retrospective cohort study, Chen and coauthors measured the number of inpatient medical consults for fee-for-service Medicare patients undergoing colectomy or total hip replacement (THR) between January 1, 2007, and December 31, 2010, at US acute care hospitals. They found wide variation across hospitals (interquartile range [IQR], 50%-91% for colectomy; IQR, 36%-90% for THR). Variation in use of medical consultations was greater for colectomy patients without complications (IQR, 47%-79%) compared with those with complications (IQR, 90%-95%); results stratified by complications were similar for THR. In an Invited Commentary, Sharma describes the challenges of standardizing medical consults.