102 patients, over 60 years old, scheduled to undergo an instrumented posterolateral lumbar spine fusion were randomized to receive recombinant bone morphogenetic protein rhBMP-2/ACS or Iliac crest bone graft (ICBG) during the procedure. The use of BMP is a significant cost burden to the patient and hospital. However, upon meticulous calculation of the aggregate cost in the 3 month period after surgery, it was observed that with the utilization of rhBMP, a net savings of $3367 was calculated, primarily due to reduced expenditure on inpatient rehabilitation, decreased hospital reimbursement, physician costs and other outpatient services rendered.