Discontinuation of Levothyroxine Therapy for Patients With Subclinical Hypothyroidism

Inclusion Criteria: * Veterans * diagnosis of SCH Exclusion Criteria: * thyroid-stimulating hormone (TSH) \> 10 milli-international units per liter (mlU/L) (at any point) * Levothyroxine (LT4) dose more than 75 mcg daily * use of antithyroid medications, amiodarone, tyrosine kinase inhibitors or lithium * history of thyroidectomy or radioactive iodine therapy * LT4 suppressive therapy for thyroid cancer, goiter, or inflammation * pregnancy or plans for pregnancy in the next 6 months * an unstable medical condition that would jeopardize safety or interfere with study participation * severe hypothyroidism-related symptoms * strong family history of hypothyroidism * severe dyslipidemia * hospitalization for major illness within the previous 4 weeks * acute coronary artery syndrome, acute myocarditis, or pancarditis with the previous 12 months * grade IV New York Heart Association heart failure * receiving services from hospice * lack of decision-making capacity * terminal medical condition for which life expectancy would be less than 6 months * not willing to stop LT4 * self-reported non-adherence to LT4 therapy * abnormal TSH at time of screening for participation (assessed during Baseline Visit)