Background: Patient-reported outcomes (PROs) responses can be used to measure patients health status, functioning, quality of life, and therapeutic response. Objectives: The objective of this study was to assess PROs and pharmacist interventions in patients prescribed specialty multiple sclerosis (MS) medications at a health system with an integrated specialty pharmacy. Methods: We conducted a single-center retrospective analysis of patients taking specialty MS medications who completed ?2 monthly refill questionnaires (MRQs) wherein PROs were collected between 1/1/2020 and 3/31/2020. MRQs are administered by a pharmacy technician when a medication refill is due and patient responses trigger pharmacist interventions. The primary outcomes were PROs regarding perceived medication effectiveness, adverse effects, and missed doses. The secondary outcome was frequency and type of pharmacist interventions prompted by MRQ responses. MRQ and intervention data were collected from the specialty pharmacy patient management database. Patient demographics and prescribed medications were collected from electronic health records. We calculated medians and interquartile ranges (IQR) for continuous variables and frequencies and percentages for categorical variables. Results: We included 335 patients: 24% male, 81% White, with median age of 52 years (IQR 45, 60). Patients filled 335 medications: fingolimod (n=74, 22%), dimethyl fumarate (n=63, 19%), interferon beta-1a (n=56, 17%), glatiramer acetate (n=56, 17%), dalfampridine (n=33, 10%), teriflunomide (n=32, 10%), interferon beta-1b (n=13, 4%), peginterferon beta-1a (n=7, 2%), and siponimod (n=1, <1%). Patients completed a median of 3 MRQs (IQR 3, 3) over three months, for a total of 1,017 total MRQs in the sample. Most MRQ responses rated medication effectiveness as excellent (n=331, 33%) or good (n=668, 66%). One percent (n=6) reported experiencing any adverse event. Ten percent (n=34) reported missing ?1 medication dose(s). Specialty pharmacists performed 136 interventions involving 65 patients, most often related to adherence or missed dose (n=39, 29%), safety therapeutic monitoring (n=36, 26%), and common side effect or toxicity (n=20, 15%). Conclusions: Patients filling medication from our integrated health system specialty pharmacy model reported low rates of missed doses and side effects, and most rated high perceived effectiveness of their medication. Integrated specialty pharmacists performed targeted interventions to ensure safe and effective medication use.