The Calculation Starts Above 3% of Total Salary
The medical expense credit is calculated on the amount of the year's medical expenses exceeding 3% of total salary.
On total salary of KRW 40 million, 3% is KRW 1.2 million. Spend KRW 1 million on medical care and the threshold is not cleared, leaving a credit of zero. Spend KRW 3 million and the KRW 1.8 million left after the KRW 1.2 million enters the calculation.
The higher the total salary, the higher the point at which the credit begins. So in a year without much medical spending, no credit may arise at all.
Conversely, in a year with substantial medical costs such as surgery or long-term treatment, the amount above 3% grows and the credit grows with it.
Who claims a family's medical expenses can also change the result because of this threshold. On the same expenses, a claimant with lower total salary has a lower 3% figure.
That does not mean anyone can pick up a family's medical expenses at will. Whether that person actually bore the expense, along with the statutory requirements, has to be checked.
The Limit Differs by Whose Expenses They Are
General medical expenses draw 15%, but the limit differs by person and some expenses draw a higher rate.
Postpartum care center costs can be separately eligible up to a set amount per birth.
Your own medical expenses are not subject to the KRW 7 million annual limit that applies to a general dependant's. In a year with large treatment costs, this difference can affect the credit actually calculated.
Medical expenses for a parent aged 65 or over can also be calculated without a limit. A general basic allowance recipient's expenses, by contrast, are subject to the KRW 7 million annual limit.
Fertility treatment draws a credit rate of 30%, above the 15% for general medical expenses. Expenses for premature infants and infants with congenital anomalies draw 20%.
Take someone on total salary of KRW 40 million spending KRW 10 million on medical care. Removing the KRW 1.2 million that is 3% of total salary leaves KRW 8.8 million.
Where that is a general basic allowance recipient's expenses, the limit recognizes only KRW 7 million, calculating to a credit of KRW 1,050,000. Where they are your own, the whole KRW 8.8 million can be used, giving KRW 1,320,000. The difference is KRW 270,000.
What Comes Off the Tax at Each Expense Level
We calculated the credit for someone on total salary of KRW 40 million by the year's medical spending, applying 15% to the amount above the KRW 1.2 million that is 3% of total salary.
KRW 270,000
The credit calculated on a year's medical expenses of KRW 3 million: 15% applied to the KRW 1.8 million left after removing KRW 1.2 million.
The table is a simple calculation at the general 15% rate. Where fertility treatment or expenses for premature infants and infants with congenital anomalies are included, the separate rate applies to those parts.
At KRW 1 million of medical expenses, the KRW 1.2 million that is 3% of total salary is not cleared and no credit arises. At KRW 2 million it is KRW 120,000, and at KRW 3 million KRW 270,000.
Once the 3% threshold is cleared, each additional KRW 1 million of general medical expenses raises the credit by KRW 150,000. Reaching a limit for the person concerned changes the calculation from there.
The calculated credit comes off calculated tax directly. Where determined tax is already low enough, though, the whole credit may not translate into an actual refund. That is set out separately in why the year-end settlement produces a refund for some and a bill for others.
Which Spending Counts as Medical Expenses
Amounts paid to a medical institution for consultation and treatment are the basic eligible category. Medicines bought for treatment or convalescence can also be included.
Glasses and contact lenses, hearing aids, and assistive devices for persons with disabilities are also included in the credit where the set requirements are met. Some items carry their own limits or evidence requirements.
Unlike other personal allowance items, the medical expense credit does not apply the age and income requirements to dependants in some cases. Whether the person is within scope and who actually bore the expense still have to be checked separately.
For a dual-income couple, who claims the same medical expenses changes the 3% threshold. Total salary of KRW 30 million gives a threshold of KRW 900,000, and KRW 50 million gives KRW 1.5 million.
Procedures purely for cosmetic or plastic purposes are excluded. Health functional foods are also generally outside the medical expense credit.
Even at the same hospital, treatment differs in handling from purely cosmetic spending. Where the distinction is unclear, checking the treatment record or receipt issued by the hospital is worthwhile.
Amounts reimbursed by indemnity medical insurance are not ultimately borne by you and have to be excluded from eligible medical expenses.
Paying KRW 3 million in hospital bills but receiving KRW 2 million in indemnity insurance, for instance, means rechecking on the basis of what was actually borne.
Not all medical expenses appear automatically in the simplified year-end settlement data. Where glasses purchases or other expenses are missing, separate evidence such as receipts can be submitted to have them reflected.
In a year with heavy medical spending, matching the figures in the simplified data against the actual receipts once is worthwhile.
Frequently Asked Questions
Is all my medical spending eligible?
No. The calculation starts above 3% of total salary. On total salary of KRW 40 million, an eligible amount arises only on medical expenses above KRW 1.2 million.
Can I include a parent's medical expenses?
Yes where the requirements are met. Medical expenses for a parent aged 65 or over are not subject to the KRW 7 million annual limit that applies to a general dependant's. Other requirements, such as whether you actually bore the expense, also have to be checked.
Is there a limit on my own medical expenses?
The KRW 7 million annual limit applying to general basic allowance recipients does not apply. So where large treatment costs arose, the amount above the 3% threshold can be calculated without a limit.
What if I received indemnity insurance?
Amounts reimbursed by indemnity insurance have to be removed from eligible medical expenses. The calculation runs on what you actually bore.
Do cosmetic procedures count?
Procedures purely for cosmetic or plastic purposes are generally outside the medical expense credit. Health functional foods are also excluded.
In a dual-income couple, who should claim?
On the same expenses, the person with lower total salary has a lower 3% threshold. Who actually bore the expenses, the family relationship, and the other requirements all have to be checked alongside.
Do a dependant's age and income matter?
Unlike other deductions, part of the medical expense credit does not apply the age and income requirements to dependants. Whether the family member is within scope and who actually paid still have to be checked separately.
How is fertility treatment calculated?
Fertility treatment draws a credit rate of 30%, above the 15% for general medical expenses. Expenses for premature infants and infants with congenital anomalies draw 20%.
Sources and basis
- Medical expense tax credit — Income Tax Act article 59-4
- Threshold — the amount exceeding 3% of total salary is eligible
- Limits and rates — general basic allowance recipients KRW 7 million a year at 15%; self and those under 6, 65 or over, and persons with disabilities, no limit at 15%
- Premature infants and infants with congenital anomalies 20%, fertility treatment 30% — no limit
- Postpartum care centers — a separate limit per birth
- Calculation basis — total salary of KRW 40 million, on a general basic allowance recipient
Tax law is subject to amendment. The law was verified on August 9, 2026.