OBJECTIVES: Deep Brain Stimulation (DBS) is a Parkinson’s disease (PD) treatment that surgically implants vibrating probes in the brain to reduce symptoms.  This study examined whether patient characteristics, hospital characteristics, or outcomes differ before and after a Center for Medicaid and Medicare Services National Coverage Decision (NCD) for DBS in PD.  METHODS: The Healthcare Cost and Utilization Project (HCUP) National Inpatient Sample for the years 2002-2004 was used for this analysis.  HCUP is sponsored by the Agency for Healthcare Research and Quality. This observational, cross-sectional study examined 12-months before and after the 04/01/2003 NCD.  Inpatient stays were identified using the PD ICD-9 code and the DBS CPT code.  Multivariate analyses tested whether discharge status or length of stay (LOS) differed after the NCD. RESULTS: This study evaluated 460 inpatient stays for PD DBS. This population had a mean age of 63.19 (range, 32-87); was 66.09% male; and 84.13% of surgeries were in large hospitals. In the post-period, patients were more likely to live in the South (p<0.0001); less likely to use a large hospital (p<0.0001); more likely to use hospitals doing fewer DBS procedures (p<0.001); and more likely to use physicians with fewer DBS procedures (p<0001). After adjusting for hospital and patient characteristics, multivariate analyses predicted that compared to the pre-period, discharge to a short/long term care facility rather than home was 3.671 times more likely to occur in the post-period [OR:3.671, CI(1.178-1.441)]; and predicted that longer LOS would occur in the post-period (Coefficient=0.3022, p=0.0003). CONCLUSIONS: This analysis suggests that compared to before the Medicare benefit expansion, the patient population after the expansion experienced worse outcomes. Further research is needed to examine whether these differences remain over time to inform Policymakers about how and why outcomes may differ before and after a benefit expansion.