OBJECTIVES: To determine differences in total healthcare expenditures among general diabetics and newly diagnosed diabetics before and after HbA1c was implemented as the standard diagnostic factor. METHODS: Medical Expenditure Panel Survey-Household component 2009 and 2011 databases were used. Annual healthcare expenditures formed the dependent variable. Demographic factors, comorbidities, prescription drug costs, medical events and utilization variables for healthcare services like visits to office-based, outpatient and inpatient facilities, emergency rooms, home health care for 2009 and 2011 formed the independent variables. Patients diagnosed within the 2009 and 2011 years, were categorized into a dichotomous new diagnosis variable. General linear regression was conducted to compare predictors of total diabetes healthcare expenditures in 2009 and 2011. RESULTS: The mean total healthcare expenditure decreased in 2011 compared to 2009 among general diabetics {$10,901 (95%CI=$9,013-$11,836) vs $11,458 (95%CI=$10,715-$12,201)} and the newly diagnosed ones {$9,462 (95%CI=$6201-$12,721) vs $8,429 (95%CI=$6793- $10,064)}. Among general diabetics in 2009, total expenditures showed significant relationships with prescription drugs, emergency room, home health care, outpatient facility and physician services expenses (all values p<0.0001). The 2011 model was similar, but included associations between office-based provider visits (p<0.0001) and previous incidences of heart attacks (p=0.008). In 2009, among newly diagnosed patients, total expenditures were significantly associated with home health facilities expenditure (p<0.0001) as opposed to no association in 2011. In both years, prescription medication, emergency room and hospital inpatient facilities expenses contributed to spending. Visits to office-based and outpatient department providers, number of home-health provider days (all values p<0.0001) and hospital discharges (p=0.0011) impacted total expenditures in 2009 and 2011 respectively. CONCLUSIONS: Due to the many variables significantly affecting diabetes health expenditures, reduction in costs could not be solely attributed to the implementation of the HbA1c diagnostic criteria. Further research on cost-effectiveness of the HbA1c factor is warranted to establish any possible association.