OBJECTIVES:  To evaluate the relationship between the numbers of patient encounters over a two year period and medication possession ratio (MPR) in patients receiving services through a voluntary support program sponsored by the manufacturer of Glatiramer Acetate. METHODS:  De-identified patient records were derived from a decision support system used for normal business operations. Patient records were included in the evaluation if they were 1) continuously enrolled in the program for a minimum of 24 months, and 2) received Glatiramer Acetate. Patients were grouped into four cohorts based upon the average number of encounters with the support services over the two year enrollment period. Chi-squared statistics were used to assess variation in categorical variable and Analysis of Variance (ANOVA) compared mean values for continuous variables. RESULTS:  A total of 10,989 patients were continuously enrolled in the support program between the dates of September 2002 and August 2011. The mean age of the study population was 45 years with no difference in mean age observed across the four cohorts (p= 0.09). The mean MPR for the study population was 0.85. Patients utilizing the support services once or twice during the two year study period had a lower MPR (0.84) than patients who utilized the services more frequently (0.87). CONCLUSIONS: Data from retail and specialty pharmacy services included within the Invision DataMartTM estimates a MPR for Glatiramer Acetate of 0.76 to 0.80. Nursing support services for multiple sclerosis enhance patient adherence by up to about 15% over that observed through retail or specialty pharmacy services alone. Costs of such service accrue to the sponsor while the benefit of improved compliance (i.e. lower medical expenditures) accrues to payers.