Hyperthyroidism (Graves’ Disease) Treatment Cost Calculator

This English page compares the three treatments for Graves’ disease (autoimmune hyperthyroidism, ICD-10 E05) in Korea — antithyroid drugs (ATD), radioactive iodine (RAI, I-131), and thyroidectomy — on both first-year and lifetime cost, using 2026 Korean drug prices, consultation fees, and benefit rules. The single most important point is that hyperthyroidism is NOT a special-case (sanjeong-teukrye) condition: the 5% special-case self-pay that thyroid CANCER patients get does not apply here. A full-text check of the current MOHW notice “Standards for Special Cases of Copayment” (No. 2026-101, effective 2026-05-01) finds no endocrine E00–E09 code at all, so ordinary benefit self-pay applies — 20% inpatient, and outpatient 30% clinic / 40% hospital / 50% general hospital / 60% tertiary (Enforcement Decree of the National Health Insurance Act, Article 19(1) Annex 2). Note the tertiary trap: a tertiary hospital charges 100% of the CONSULTATION fee plus 60% of everything else, not a flat 60%, so moving to a local clinic once stable can cut long-run follow-up cost by more than half. The second surprise is that the drugs are almost free: per Korea Pharmaceutical Information Center 2026 reimbursement prices, methimazole 5mg is KRW 39/tablet, propylthiouracil (PTU) 50mg is KRW 38/tablet (raised from 34 on 2026-01-01), and levothyroxine 100mcg (Synthyroid 0.1mg) is KRW 35/tablet — so maintenance ATD runs about KRW 1,200–2,400 a month and lifelong levothyroxine about KRW 1,050 a month (30% pharmacy self-pay). Cost is therefore driven by consultations and lab tests, not medication. A third rule matters a lot: thyroid function tests are covered for only 3 items (MOHW notice No. 2016-226) out of T3, Free T3, T4, Free T4, and TSH — TSH + free T4 + T3 is exactly 3 and fully covered, but adding free T3 makes 4 and the excess falls under selective benefit at a 90% self-pay rate (notice No. 2022-283, effective 2023-01-01); TRAb (TSH-receptor antibody) is separately covered for Graves’ diagnosis, treatment-response, and relapse prediction. On treatment choice, a nationwide NHIS cohort of 452,001 Korean Graves’ patients (Endocrinol Metab 2024) found initial therapy was ATD 98.0%, surgery 1.3%, RAI 0.7%, with initial failure rates of 58.5% / 2.1% / 21.3% and remission at 5 years of 46.8% (ATD) versus 91.0% (RAI). Korea’s national health portal (KDCA) puts ATD remission at 40–50% with about 50% relapsing after withdrawal, mostly within the first year; residual TRAb at withdrawal raises relapse to 80–100%. RAI in Graves’ is an OUTPATIENT treatment — the Korean median initial dose is 10 mCi (IQR 10–15), far below the 30 mCi cutoff hospitals use for mandatory isolation admission; the legal basis is the Nuclear Safety and Security Commission notice “Technical Standards for Radiation Safety Management in Medicine”, Article 12 and Annex 2, which set I-131 discharge limits at 1.2 GBq (33 mCi) residual activity, 0.07 mSv/h at 1 m, and a 5 mSv family dose limit. So unlike high-dose thyroid-cancer ablation, Graves’ RAI incurs no isolation-ward cost. RAI does cause hypothyroidism in about 50% long-term (overseas cohorts: 24–25% at 1 year, 59–60% at 10 years, then about +3%/year), and total thyroidectomy causes it essentially 100% of the time, meaning lifelong levothyroxine — though at KRW 35/tablet that is a small burden. Korean surgical outcomes (Asan Medical Center, 350 cases, Int J Endocrinol 2015) show permanent hypoparathyroidism 0.4% and recurrent laryngeal nerve injury 0%. Eye disease changes the calculus: RAI worsens or triggers Graves’ orbitopathy in about 15% versus 3% for methimazole (Bartalena, NEJM 1998, 443-patient RCT), but adding prednisone prophylaxis (0.3–0.5 mg/kg/day starting the day of RAI, tapered over about 12 weeks, per the 2026 Korean TED framework) reduced progression to zero. Smoking raises orbitopathy risk about 4.4-fold in an overseas meta-analysis, though a Korean NHIS cohort did not find a statistically significant link (men p=0.074, women p=0.432). Teprotumumab (Tepezza) received Korean MFDS approval on 2026-04-30 for moderate-to-severe thyroid eye disease but remains NON-COVERED with no published Korean price and launch expected in late 2026, so it is excluded from the figures here. On tax, the medical-expense tax credit (Income Tax Act Article 59-4(2)) has no KRW 7,000,000 cap for the taxpayer themselves (subparagraph 2(a)), those 6 and under, 65 and over, the disabled, or registered serious-illness patients — but Graves’ disease is NOT a serious illness, so an ordinary dependent falls under subparagraph 1 and IS capped at KRW 7,000,000; the credit rate is 15% of the amount exceeding 3% of total salary. Accuracy caveat: drug prices, 2026 clinic consultation fees (first visit KRW 18,840 / revisit KRW 13,370), self-pay rates, test benefit rules, and I-131 capsule prices are verified from primary sources, but individual test fees and surgery totals are ESTIMATES because the relative-value fee schedule is published only as an attachment to the MOHW notice. This is planning guidance based on 2026 Korean rules, not medical advice or an insurer decision.