Background: To identify pts with TKI resistance in a timely manner, the National Comprehensive Cancer Network (NCCN) guidelines recommend monitoring pts at specific time points. We evaluated the relationship between NCCN guidelines and current treatment response monitoring patterns and outcomes of CP-CML pts in community practice. Methods: A retrospective longitudinal cohort study was conducted on newly diagnosed CP-CML pts initiating TKI therapy from Jan 1, 2008 to Dec 31, 2010. Data was extracted from the MSH/USON iKnowMed electronic health record database and chart reviews through Jul 31, 2012. Pts were stratified by presence of any cytogenetic monitoring by 12 mos or any molecular monitoring by 18 mos. Results: Of the 410 pts identified, 91% received imatinib and 9% received dasatinib/nilotinib. Median follow-up was 28 mos. Cytogenetic and molecular monitoring did not occur in 69% and 27% of pts, respectively. BCR-ABL mutation testing occurred in 10% of pts who were monitored for response. Pts ≥65 yrs old (vs <65 yrs, p<0.01), with public insurance (vs private insurance, p<0.001), or with Karnofsky Score ≤80 (vs >80, p<0.05) were less likely to have cytogenetic monitoring. Similar differences for age (p<0.05) and insurance (p<0.001) were seen for molecular monitoring. For pts with available monitoring results, 36% had complete cytogenetic response by 12 mos, and 59% had major molecular response by 18 mos. 4-yr overall survival (OS) rates were higher in pts with cytogenetic (98% vs. 89%, P=0.0003) or molecular (95% vs. 82%, P≤0.0001) monitoring vs. those with no monitoring. Conclusions: In these CP-CML pts, 69% did not receive any cytogenetic monitoring by 12 mos and 27% did not receive any molecular monitoring by 18 mos. Obstacles related to monitoring may include age, payer status, and performance status. Pts that were monitored for cytogenetic and molecular responses had significantly higher OS rates at 4 yrs. Increasing the proportion of pts that are monitored according to NCCN guidelines in the community setting could improve patient outcomes.