Background: In 2007, the NCCCP pilot program launched with 16 sites and a goal to improve quality of care, reduce cancer disparities and increase participation in clinical trials. In 2008, NCCCP began to participate in the Commission on Cancer Rapid Quality Reporting System (RQRS). An evaluation of NCCCP in 2010 assessed changes in cancer care quality among the sites before vs. after program implementation compared to non-NCCCP hospitals during the same time period (Halpern et al. 2013). Our current analysis examines if improvements in quality were sustained. Methods: Conducted a retrospective analysis of patients diagnosed and receiving all or part of their initial cancer treatment at an NCCCP facility. Compared concordance rates for 6 NQF- approved quality of care measures (3 breast, 2 colon and 1 rectal) for patients diagnosed between 2006-2007 (pre-NCCCP), 2008-2010 (early NCCCP) and 2011-2013 (later NCCCP). Results: The sample included 17,288 breast, 6,655 colon and 569 rectal cancer patients. Patient-level concordance rates improved significantly for all 6 measures and were sustained for 5. Breast cancer measures showed the greatest improvement from pre-NCCCP and were subsequently sustained. Hormone therapy for hormone receptor positive breast cancer increased from 51% (pre) to 90% (early) to 92% (later). Radiation therapy for breast conserving surgery increased from 72% to 93% to 92%. Colon cancer measures also showed sustained improvements with adjuvant chemotherapy for stage III cancer increasing from 72% to 90% to 89%. However, adjuvant chemotherapy for stage III rectal cancer improved from baseline (83%) to early NCCCP (90%) but then returned to pre-NCCCP rates (83%) later in the program. Significant changes were also seen in disparate populations. Conclusions: Quality of care measures at NCCCP sites increased after program initiation, and this increase was largely sustained over time. Improvement in recording of treatment administration due to the RQRS was a factor in increasing concordance. Concurrent NCCCP activities, including a working group to improve RQRS reporting and presentations of NCCCP results to the participants, may have helped sites significantly improve and sustain quality cancer care.