215 Background: Advances in therapy have led to an increase in survival in women with HER2+ metastatic breast cancer (MBC). However, changes in health-related quality of life (HRQoL) and productivity related to longer survival have not been well studied. Methods: A one-time survey was administered to women recruited through select clinics and advocacy organizations. Inclusion criteria were female sex, age 18+, US residence, and having HER2+ MBC. HRQoL and impact on productivity were assessed using several validated instruments: EQ Visual Analogue Scale (EQ VAS), Functional Assessment of Cancer Therapy-Breast (FACT-B), Rotterdam Symptom Checklist (RSCL), Distress Thermometer (DT), PROMIS Applied Cognition-Abilities-8a, and Work Productivity & Activity Impairment Questionnaire-Specific Health Problem (WPAI-SHP). Regression analyses were conducted to compare differences in measures by years since diagnosis (< 6 vs. ≥ 6 years), adjusting for age. Results: A total of 404 women participated in the survey. Mean age was 54.2 years, 91.6% were white, and 27.5% reported it had been ≥ 6 years since their HER2+ MBC diagnosis. In unadjusted analyses, women living with MBC ≥ 6 years reported significantly greater HRQoL (FACT-B, p=0.01) and emotional well-being (FACT-B EWB, p<0.01), lower distress (DT, p = 0.02; RSCL Physical & Psychological Symptom Distress, p = 0.01 & p = 0.03), and lower impairment due to MBC (WPAI-SHP, p<0.05). No differences were seen in EQ VAS or PROMIS scores. In age-adjusted analyses, women living with MBC ≥ 6 years had significantly greater emotional well-being (FACT-B EWB, p<0.01), lower distress (DT, p<0.05; RSCL Physical Symptom Distress, p = 0.03), and lower activity impairment due to breast cancer (WPAI-SHP, p<0.01). There were no major differences in findings between women recruited online versus in clinics. Conclusions: Women living with HER2+ MBC for ≥ 6 years may experience improvements in HRQoL compared to women diagnosed more recently. This may suggest that women adjust to the disease over time; however, potential selection biases in the recruitment of survey respondents may limit generalizability of these findings. Further investigation of temporal changes in HRQoL is warranted.