OBJECTIVES:  To evaluate the impact of patient characteristics, behaviors and attitudes on teriparatide adherence in a Medicare Part D plan with a coverage gap.  METHODS: Medicare Part D plan members 18 years and older with at least one claim for teriparatide in 2009 and continuous enrollment January 1, 2009 – December 31, 2009 were identified in an administrative claims database.  A questionnaire was mailed to members that met study criteria. Descriptive analyses were conducted to evaluate the characteristics of the study population.  Logistic regression analyses were conducted to identify factors that predicted discontinuation with teriparatide.  RESULTS: Out of the 3656 mailed questionnaires, 522 (14%) were completed; 204 (39.1%) members were currently taking teriparatide, 171 (32.8%) completed therapy, 133 (25.5%) discontinued, and 14 (2.7%) did not indicate teriparatide use status.  No differences in the age or gender of completers versus discontinuers were noted.  Factors associated with an increased likelihood of discontinuation were: using less teriparatide during the coverage gap (Odds ratio [OR]=10.71; Confidence Interval [CI]=1.54, 74.32; p<0.02), talking to one’s doctor about cutting down on teriparatide medication costs (OR=4.07; CI=1.44, 11.51; p<0.01), having an annual income $30,000-$59,999 (OR=4.74; CI=1.38, 16.27; p<0.03), and taking a break from teriparatide during therapy (OR=4.16; CI=1.15,15.02; p<0.03).  Factors associated with a decreased likelihood of discontinuation included:  having a belief that taking teriparatide is important to being healthy (OR=0.65; CI=0.50, 0.85; p<0.001) and beliefs about seeing improvements in one’s osteoporosis (OR=0.80; CI=0.65, 0.99; p<0.05).  CONCLUSIONS: Factors that suggested cost-cutting behavior, specifically during the coverage gap, were associated with discontinuation, whereas beliefs about the effectiveness of teriparatide were associated with a decreased likelihood of discontinuation.  Understanding patient beliefs, attitudes and behaviors toward therapy may be helpful in predicting patient adherence to teriparatide.