Korean Health Premium Income Adjustment and Settlement Calculator

Compare 2026 Korean regional or employee non-payroll health premiums before and after income adjustment, then plan next-November settlement using three full-year income scenarios and conditional installments.

2026 Korean health insurance · unchanged status throughout the year

Replace the example values with your records. Compare immediate payment changes with settlement of the entire 2026 year, expected in November 2027. Income increases and decreases can be modeled for business, employment, interest, dividends, pensions and other income.

1. Application and adjustment period

Use an NHIS-confirmed start month for first-day or November–December exceptions. Retroactive cases and extensions into the next year are outside scope. Employees must exclude current payroll remuneration and employer shares.

2. Previous and adjusted annual income

Regional cases require one income-bearing insured and zero income for other members. Enter business/other income after expenses and exclude non-taxable amounts. The financial field covers only ordinary interest/dividends under Income Tax Act 14(3)(6): up to KRW 10 million is excluded, above it the whole amount is included. Select outside scope for overseas, unwithheld, special or unknown classifications. Employment/public pensions use 50% evaluation; employee non-payroll income uses a proportional KRW 20 million deduction.

January–October baseline: 2024 income + 2025 public pension
November–December baseline: all 2025 income

Public pension uses 2025 records in both periods: 0 KRW

Annual income used after adjustment

3. Actual 2026 annual income scenarios

Include income earned before retirement or closure and new income after adjustment, for all January–December. Entering income only from the adjusted period understates settlement.

Low · Expected final annual income
Base · Expected final annual income
High · Expected final annual income

4. Annual payments and installment reference

Actual totals must cover 2026 health/care only; exclude other-year settlements, arrears and employer shares. Use actual totals if reporting new income changed later bills. The installment threshold is 100% of the settlement-month regular premium and can differ from today’s estimate.

5. Reporting new income after adjustment

The statutory reporting window runs from the first day through the end of the following month. Holiday extensions are not determined. This date alone does not change modeled premiums; reflect later bills through actual annual payments.

Current-year payment changes and settlement

★ Provisional current-year payment decrease

3,455,460 KRW

Adjusted monthly health + care

22,800 KRW

Annual paid/projected total

1,425,420 KRW

Adjustment starts: 2026-04 · 9 months · Following-month default estimate

Baseline Jan–Oct health / care
359,500 KRW / 47,240 KRW
Baseline Nov–Dec health / care
359,500 KRW / 47,240 KRW
Adjusted health / care
20,160 KRW / 2,640 KRW
Annual paid health / care
1,259,940 KRW / 165,480 KRW

A provisional decrease is not permanent savings. The whole 2026 year is recalculated using actual income, so reduced income can still produce an additional payment. A negative decrease means higher current payments. This does not assume the same automatic settlement without application.

Expected November 2027 settlement · 2026 income year

For each scenario, final monthly premiums × 12 minus annual paid premiums give the settlement. Refunds may be offset against other dues; payment dates are not established. The 2026 income-year rates apply rather than 2027 rates.

Health and care settlements and total burden for three actual-income scenarios
ScenarioFinal monthly totalHealth settlementCare settlementTotal settlementSettled annual burden
Low
Refund or offset to review		22,800 KRW-1,018,020 KRW-133,800 KRW-1,151,820 KRW273,600 KRW
Base
Refund or offset to review		81,340 KRW-397,140 KRW-52,200 KRW-449,340 KRW976,080 KRW
High
Estimated additional payment		162,690 KRW465,660 KRW61,200 KRW526,860 KRW1,952,280 KRW

Low · Refund or offset to review: 1,151,820 KRW

No additional amount or below threshold

No additional payment means no installment schedule. This does not imply installment refunds.

Base · Refund or offset to review: 449,340 KRW

No additional amount or below threshold

No additional payment means no installment schedule. This does not imply installment refunds.

High · Estimated additional payment: 526,860 KRW

Future billed threshold unverified

Conditional installment budget assuming approval · 12 payments · First / final: 43,900 KRW / 43,960 KRW

View each payment budget
  1. 2027-11: 43,900 KRW
  2. 2027-12: 43,900 KRW
  3. 2028-01: 43,900 KRW
  4. 2028-02: 43,900 KRW
  5. 2028-03: 43,900 KRW
  6. 2028-04: 43,900 KRW
  7. 2028-05: 43,900 KRW
  8. 2028-06: 43,900 KRW
  9. 2028-07: 43,900 KRW
  10. 2028-08: 43,900 KRW
  11. 2028-09: 43,900 KRW
  12. 2028-10: 43,960 KRW

Up to 12 payments require the settlement-month regular-premium threshold and timely NHIS application/approval. An unverified reference produces only a conditional budget. Small balances use fewer payments to avoid zero-value installments. Listed months start at 2027-11 for planning and are not actual due dates.

Monthly provisional payment comparison for 2026

Compare the no-adjustment baseline with the adjustment plan. Actual annual payment totals are not redistributed into these modeled rows.

Monthly baseline and planned health/care totals with provisional differences
MonthBaseline totalPlanned totalProvisional decrease
2026-01406,740 KRW406,740 KRW0 KRW
2026-02406,740 KRW406,740 KRW0 KRW
2026-03406,740 KRW406,740 KRW0 KRW
2026-04 · adjusted406,740 KRW22,800 KRW383,940 KRW
2026-05 · adjusted406,740 KRW22,800 KRW383,940 KRW
2026-06 · adjusted406,740 KRW22,800 KRW383,940 KRW
2026-07 · adjusted406,740 KRW22,800 KRW383,940 KRW
2026-08 · adjusted406,740 KRW22,800 KRW383,940 KRW
2026-09 · adjusted406,740 KRW22,800 KRW383,940 KRW
2026-10 · adjusted406,740 KRW22,800 KRW383,940 KRW
2026-11 · adjusted406,740 KRW22,800 KRW383,940 KRW
2026-12 · adjusted406,740 KRW22,800 KRW383,940 KRW

Reporting, application checklist and saving

  1. Confirm the reason, recognized start month/year, membership and household changes, fixed property amount and reductions with NHIS.
  2. Check required settlement consent, identity and business/employment/income evidence. NTS simplified payment statements can simplify evidence for personal-service contracts; a termination certificate is not universally required.
  3. Distinguish online applications for decreases from office/mail/fax procedures for increases. Check the 90-day cancellation window and the bar after settlement.
  4. Report new income within the following-month statutory window; verify annual payments, the settlement-month reference premium, requested installments and approval.
Official application guidance

Check property and ordinary regional premiums separately

Rules checked: 2026-11-07 · Decree Article 41-2 · Enforcement Rule Article 44 · NHIS Charter

Health 7.19%; care 0.9448% ÷ 7.19%; health maximum KRW 4,591,740 and regional income minimum KRW 20,160. Each premium is rounded down to KRW 10 for planning; actual billing rounding may differ.

Related calculators

Connect the adjustment application to the later settlement

After closing a business, retiring or finishing a freelance contract, your current earnings may fall while Korean National Health Insurance bills still reflect older income data.
An income adjustment changes the provisional billing basis, followed by a later reconciliation with confirmed annual income.
A lower bill today therefore needs to be considered alongside the amount that might become payable later.

This calculator connects a 2026 monthly payment plan to the expected November 2027 settlement, shown as 2027-11.
It compares provisional payments before and after adjustment, three annual-income outcomes, additional payment or refund review amounts, and an installment budget.
The annual burden after settlement helps separate temporary cash-flow relief from a permanent reduction in the premium attributable to that income year.

South Korea only, using verified 2026 rules.
Since January 2025, adjustment can cover increases and decreases across business, earned, interest, dividend, pension and other income.
The interface combines interest and dividends into one financial-income field.

Supported insurance status and exclusions

Regional household with one income earner

Use this mode only for an unchanged regional household throughout 2026, with one income-bearing insured person and zero income for other household members.
The property health-premium component must remain constant.
Households with several income earners need individual financial-income threshold assessment before aggregation and are outside this model.

Employee non-payroll income

This mode assumes employee coverage throughout 2026 and assesses non-payroll income premiums.
Exclude remuneration already assessed through the employer, the employer share and the ordinary payroll premium.
The regional property component and regional minimum do not apply to this mode.

A retirement reason does not establish that insurance status remained unchanged throughout the year.
Switching between employee and regional status, becoming or ceasing to be a dependent, household changes, reductions, retrospective status changes, and special rental-income classifications require individual review.
Select the out-of-scope option in those cases; a withheld result means further review is needed and does not indicate a zero premium.

The property input is the monthly health-premium component from an NHIS notice, rather than a fresh valuation of taxable property or rent deposits.
For property deductions and regional premium composition, see the regional health insurance calculator.
Dependent eligibility and voluntary continuation require their own checks.

What the annual income fields mean

Business and other income

Business income means the income amount after relevant expenses, rather than sales revenue.
Other income also needs the income amount used by NHIS, rather than an unverified gross payment.

Earned income and public pension

Enter the relevant taxable earnings and NHIS-recognized public pension data before the calculator applies the 50% evaluation rate.
Halving an input yourself would apply that reduction twice.

Ordinary interest and dividends

The supported financial field is limited to ordinary income covered by Income Tax Act Article 14(3)(6).
Enter the full combined annual amount.
Foreign, unwithheld or otherwise specially classified financial income requires a separate review.

Adjusted income and final scenarios

The adjusted vector is the annual income basis proposed for provisional billing.
Each final scenario is an estimate of the entire January-to-December income amount.
No income after closure does not necessarily mean no income for the full year.

The low, base and high scenarios are user assumptions, with no built-in probabilities or predicted growth rates.
Initial values are a synthetic worked example.
Use your own income records and replace modeled payments with actual annual health and care totals when they become available.

Reference-year timing and the first adjusted month

Enforcement Decree Article 41(3) normally uses income data from two years earlier for January through October and from the previous year for November and December.
Public pension is an exception: the previous year applies in both periods.
For 2026, enter 2024 ordinary income for the early period and 2025 ordinary income for the late period; public pension must use the same 2025 amount for both.

Default timing versus NHIS-confirmed timing

The standard period in NHIS rules runs from the month after the application through December of that year.
An application on March 15, 2026 therefore models April through December, or nine adjusted months.
Different operational starting periods, including first-day applications and year-end exceptions, need confirmation rather than an automatic assumption.

The confirmed-month mode supports a month in 2026 from the application month onward.
A December application under the default next-month rule has no adjusted month within this 2026 model, so calculation is withheld unless a supported December start has been confirmed.
A next-year extension or retrospective start before the application month needs separate review.
Check the monthly comparison to see the November reference-data change even when adjustment is not yet in effect.

2026 rates, income weighting and premium limits

The health rate is 7.19%, and the income-based long-term care rate is 0.9448%.
Care is calculated as health premium × 0.9448 ÷ 7.19.
The approximately 13.14% care-to-health ratio is rounded for display and is not the calculation constant.
This planning model truncates health and care separately to KRW 10, so an actual NHIS notice can differ in its billing rounding.

Regional income first, then property

Let W be annual business, includable financial and other income in full, plus 50% of earned income and public pension.
For W ÷ 12 at or below KRW 280,000, the income health component is KRW 20,160.
Above that boundary, use W × 7.19% ÷ 12.
Add the fixed property component and apply the monthly health maximum of KRW 4,591,740.
Applying a minimum only to the combined income-and-property total would give a different result.

Employee non-payroll deduction

Let S be total includable annual income before the earned-income and pension weighting.
If S is at or below KRW 20,000,000, the non-payroll premium is zero.
Above it, evaluated monthly income is (S − 20,000,000) × W ÷ S ÷ 12.
The deduction is allocated proportionally before evaluation; subtracting KRW 20 million directly from W is incorrect.
For KRW 20 million business income plus KRW 20 million earned income, S is KRW 40 million, W is KRW 30 million, and the evaluated annual amount after deduction is KRW 15 million.

For ordinary financial income within scope, a combined interest-and-dividend amount at or below KRW 10,000,000 is excluded; above that threshold the full amount enters the assessment.
This creates a threshold effect, and the result should not be read as a smooth marginal charge on the excess alone.

Use the calculator step by step

  1. Confirm unchanged 2026 insurance status, household and supported income classification.
    Enter the change date and application date, using the out-of-scope option when those assumptions do not hold.
  2. Copy annual reference income for both billing periods and the fixed property component from your records.
    Enter the adjusted annual income vector and three possible full-year final income vectors.
  3. Keep the next-month default as a timing assumption, or choose a supported starting month already confirmed by NHIS.
    Do not treat an exception as approved merely because a month can be selected.
  4. Use actual annual health and care payment totals when later reports or billing changes make the model inaccurate.
    Exclude other-year settlements, arrears payments and the employer share.
  5. Compare settlement outcomes and save the result with its assumptions.
    Follow through with the adjustment application, new-income reporting, notice reconciliation and any installment application.

Worked example: a March application

Assume regional status with no property premium, KRW 60,000,000 business income in each old reference vector, zero adjusted income and no other income.
An application on March 15, 2026 starts adjustment in April under the default model.
The old monthly premium is KRW 359,500 health plus KRW 47,240 care, totaling KRW 406,740.
The adjusted monthly amount is KRW 20,160 health plus KRW 2,640 care, totaling KRW 22,800.

Synthetic 2026 payment plan for a March income-adjustment application
Period or measureCalculationTotal KRW
January–March406,740 × 31,220,220
April–December22,800 × 9205,200
Modeled annual paymentsBoth periods combined1,425,420
Provisional payment reduction383,940 × 93,455,460

The provisional reduction describes the difference in payments before settlement.
It is not an unconditional gain created by applying for an adjustment.
For this example, modeled annual health payments are KRW 1,259,940 and care payments are KRW 165,480.
Actual payment totals should replace these values if the notices changed during the year.

Three final-income outcomes for the full year

Health settlement equals the reassessed monthly health premium multiplied by 12, minus annual health already paid.
Compute care separately, then add the two differences.
The relevant reassessment covers the full supported year, not only the nine adjusted months.
The expected notice month is 2027-11, but the reassessed 2026 premiums still use the 2026 rates and limits.

KRW 0 business income

Annual burden KRW 273,600
Settlement −1,151,820 KRW

KRW 12,000,000 business income

Annual burden KRW 976,080
Settlement −449,340 KRW

KRW 24,000,000 business income

Annual burden KRW 1,952,280
Settlement +526,860 KRW

KRW 24 million remains below the old KRW 60 million income basis, yet it produces an additional bill because provisional adjusted income was zero.
A negative amount identifies a possible refund or offset rather than a guaranteed cash payment.
The model does not assume that a person who never applied for adjustment automatically receives the same settlement.
No scenario probability or approval likelihood is inferred from these examples.

Report new income and check the evidence

Under Enforcement Decree Article 41-2(3), income arising after adjustment in the relevant year must be reported within one month from the first day of the following month.
For new income dated August 20, 2026, the ordinary reference reporting window is September 1–30, 2026.
December income points to a window in January of the next year.
The displayed dates do not automatically adjust for holidays or individual exceptions; verify the actual NHIS deadline.

Prepare reason-specific information

  • Check consent to settlement and identification, together with evidence of business suspension, closure or the end of employment as relevant.
  • Where an income certificate is used, check the procedure for a previous-year certificate issued on or after July 1 of the application year.
  • Personal-service termination may be verified through National Tax Service simplified payment statements without a separate termination certificate.
    Missing or incorrect statement data can change the evidence needed.
  • Online applications are provided for income decreases.
    For increases or data issues, check available branch, postal or fax procedures.

Cancellation is generally limited to 90 days from application and is unavailable once the relevant settlement has already been made.
Other benefits based on premium or income information, such as dependent coverage or out-of-pocket ceilings, can need separate review.
After reporting new income, reconcile changed notices using actual annual payments and save the updated assumptions.

Installment budgets, refunds and offsets

NHIS Articles of Incorporation Article 43 provides for up to 12 installments when the additional settlement meets at least 100% of the monthly premium in the settlement billing month, with application by the payment deadline.
For this 2026 income-year estimate, that monthly reference belongs to the 2027 settlement notice.
Do not substitute today’s premium as a verified future amount.
Enter the confirmed health-and-care monthly total when available; otherwise the requested schedule remains conditional.

Preparing KRW 526,860 over twelve payments

Assuming the amount criterion and NHIS approval, a planning allocation is KRW 43,900 for each of the first eleven payments and KRW 43,960 for the last payment.
The payments sum to KRW 526,860.
This tool rounds the earlier allocations down to KRW 10 and leaves the remainder to the last one.
Actual notice rounding and payment dates take precedence.
A refund or an amount below the confirmed criterion is not labeled eligible for additional-bill installments.

A refund estimate should be kept separate from spendable cash because other premiums due can be offset against it.
Corrected income can also change the amount later.
Increasing the number of installments spreads the budget without reducing the total settlement balance.

Frequently asked questions

Does retirement immediately reduce my health premium?

Current earnings do not automatically replace the older income data used for billing.
An adjustment application and review of the reason are needed.
The default modeled start is the month after application; enter another first month only after NHIS confirms it.

Does settlement cover only the adjusted months?

No.
NHIS rules provide for reassessment of all months of the relevant year.
This tool models January through December with unchanged insurance status.
A person switching from employee to regional coverage during the year needs a separate period-based review.

Is a contract-termination certificate always required?

No.
For personal-service business income, NHIS may verify termination through simplified income statements supplied by the National Tax Service without a separate termination document.
Missing or incorrect data can require further evidence.
Check the documents required for your specific reason.

Can income fall and still lead to an additional settlement bill?

Yes.
Settlement compares the premium based on confirmed annual income against what you actually paid during that year.
Income can be lower than the old reference amount but higher than the provisional adjusted amount, leaving a balance to pay.

Does choosing twelve installments submit an application?

No.
The additional settlement amount must meet the billing-month premium criterion, and an application must be made within the payment deadline.
NHIS confirmation is separate.
Without a verified 2027 billing-month amount, the displayed schedule is a conditional budget.

Should I enter only financial income above KRW 10 million?

Enter the full annual ordinary interest and dividend amount within the supported financial-income category.
The calculator excludes the total at or below KRW 10 million and includes the entire total above it.
Foreign, unwithheld and other special financial-income classifications are outside scope.

Should an employee include their regular salary?

Do not enter remuneration already assessed through the current employer payroll premium.
This mode covers non-payroll income only, with no regional minimum or property component.
Use the separate April settlement calculator for payroll remuneration.

Is a negative settlement guaranteed to arrive as cash in November 2027?

No.
A negative estimate identifies an amount to review for refund or offset.
NHIS may offset it against other premiums due, and corrected income information can change the settlement.
Check the actual notice and payment process before treating it as available cash.

Official sources and verification date

Verified November 7, 2026 using the Korean National Law Information OPEN API and current official service guidance.
The Health Insurance Enforcement Decree version is effective October 1, 2026, and the Enforcement Rule version is effective September 28, 2026.
Recheck annual rates and limits, NHIS timing exceptions, evidence requirements, installment procedures and actual notice rounding when updating this calculator.

Turn the result into a notice and application checklist

Save the reference years, first adjusted month, estimated annual income and separate health and care payment totals.
Confirm the adjustment reason and effective period with NHIS, report new income, and compare the later settlement notice before applying for installments.
This calculator does not submit an application or execute a premium payment or refund.

Open the official adjustment service guidance · Compare an employee payroll April settlement