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2. Cigna. Cigna and Express Scripts introduce patient assurance program to cap out of pocket costs at $25 per 30-day insulin prescription. Published April 3, 2019. Accessed January 7, 2020. https://www.cigna.com/newsroom/news-releases/2019/cigna-and-express-scripts-introduce-patient-assurance-program-to-cap-out-of-pocket-costs-at-25-per-30-day-insulin-prescription
3. IBM Watson Health. IBM MarketScan Research Databases for health services researchers. Published April 2019. Accessed February 8, 2020. https://www.ibm.com/downloads/cas/6KNYVVQ2
4. Internal Revenue Service. 26 CFR 601.602: tax forms and instructions. Rev. proc. 2017-37. Accessed February 28, 2020. https://www.irs.gov/pub/irs-drop/rp-17-37.pdf