In a month when your medical bills run high, do you stop at paying "up to the ceiling" with your Myna insurance card or a ceiling-amount certificate? Japan's high-cost medical care benefit (kogaku ryoyohi) has two further mechanisms that cut your burden even more. One is household aggregation (setai gassan): adding up family members' out-of-pocket payments (21,000 yen or more per bill) to recover the amount over the ceiling. The other is the multiple-time reduction (tasukai gaito): if you receive the benefit three or more times in the most recent 12 months, the ceiling itself drops from the fourth time on. Monthly ceilings were raised from August 2026, but the multiple-time amounts were left unchanged — so the gap between those who know and those who don't has actually widened. We sort out the aggregation conditions, worked examples with the post-revision figures, the trap where changing jobs resets your count, and how to claim back the past two years.
First, the basics: ceilings from August 2026, the "multiple-time reduction" and the new annual cap
For the fundamentals of the high-cost medical care benefit (monthly ceilings per calendar month, how to use it with the Myna insurance card), see our guide to the high-cost medical care benefit. Here we only pin down the post-revision figures used in this article. For treatment from August 2026 on, the ceilings for people under 70 are as follows.
| Bracket | Approximate annual income | Monthly ceiling (from Aug 2026) | Multiple-time (4th time on) | Annual cap (new) |
|---|---|---|---|---|
| A | Approx. 11.6 million yen and above | 270,300 yen + (medical costs − 901,000 yen) × 1% | 140,100 yen | 1.68 million yen |
| B | Approx. 7.7–11.6 million yen | 179,100 yen + (medical costs − 597,000 yen) × 1% | 93,000 yen | 1.11 million yen |
| C | Approx. 3.7–7.7 million yen | 85,800 yen + (medical costs − 286,000 yen) × 1% | 44,400 yen | 530,000 yen |
| D | Up to approx. 3.7 million yen | 61,500 yen | 44,400 yen | 530,000 yen |
| E | Exempt from residence tax | 36,900 yen | 24,600 yen | 290,000 yen |
- The multiple-time amounts were left unchanged by the revision. In bracket C, the normal monthly ceiling is 85,800 yen + 1%, but from the fourth time it is 44,400 yen — a difference of more than 40,000 yen a month, wider than before the revision (when the gap was against 80,100 yen). The longer your treatment, the more the multiple-time reduction is worth.
- An annual cap was newly introduced (a ceiling on patient burden for treatment from August through July of the following year). It is a relief measure for people in long-term care whose months keep falling just short of the ceiling and who therefore cannot reach the multiple-time reduction; the excess is reimbursed by the insurer (for the time being, operation is premised on the patient applying).
- People aged 70 and over have a separate bracket table (with an outpatient special rule), but the concepts of the multiple-time reduction and household aggregation are the same.
Household aggregation: add family bills of "21,000 yen or more" and recover the excess
Even if no single person's payment at a single hospital reaches the ceiling, if the combined out-of-pocket payments of family members covered by the same health insurance exceed the ceiling, the excess is paid out as a high-cost medical care benefit. There are three conditions.
- Being covered by the same health insurance (the same insurer). For company employees, the aggregation unit is "the insured person plus their dependents"; for National Health Insurance (NHI), it is "NHI members of the same household."
- For people under 70, only out-of-pocket payments of 21,000 yen or more per bill count toward aggregation. Payments of 20,999 yen or less cannot be included, no matter how many there are (payments for people aged 70 and over can be aggregated in full regardless of amount).
- The treatment must fall in the same calendar month (1st to the last day). Spanning two months means separate calculations.
How to count "one bill" is the first stumbling block. Count per patient, per medical institution, inpatient and outpatient separately, and medical and dental separately. Payments to an outside pharmacy are included with the medical institution that issued the prescription.
Worked example: a family of three in bracket C (figures from August 2026)
The husband (Kyokai Kenpo, bracket C) is hospitalized, and in the same month his dependent wife and child also see doctors:
- Husband's hospitalization: medical costs 200,000 yen → 30% at the counter = 60,000 yen (21,000 yen or more → counts toward aggregation)
- Wife's outpatient care: medical costs 100,000 yen → 30,000 yen (21,000 yen or more → counts toward aggregation)
- Child's outpatient care: medical costs 60,000 yen → 18,000 yen (under 21,000 yen → cannot be aggregated)
Aggregated out-of-pocket payments: 60,000 + 30,000 = 90,000 yen (medical costs for the counted portion: 300,000 yen)
Ceiling: 85,800 yen + (300,000 yen − 286,000 yen) × 1% = 85,940 yen
High-cost medical care benefit paid: 90,000 yen − 85,940 yen = 4,060 yen
No one reaches the ceiling individually, yet a refund arises once you aggregate — that is household aggregation. Even if the amount looks small, in a month when hospitalizations overlap or treatment drags on, it can reach tens of thousands of yen.
Stumbling blocks: patterns where you cannot aggregate
- A dual-income couple on separate health insurance (the husband on his employer's health insurance society, the wife on her employer's Kyokai Kenpo, etc.): even if they share the same residence register, the insurers differ, so they cannot aggregate. Each insurance judges the ceiling separately.
- Living with a parent who is on NHI or the medical system for people 75+ while you are on your company's health insurance: again, different insurance, so no aggregation. Note that the system for those 75 and over is a separate, individual-based scheme.
- Payments that fall just short of 21,000 yen: for people under 70, they are excluded from the calculation (even if unusable for the high-cost benefit, they still count toward the medical expense deduction, so do not throw away the receipts).
- Hospital stays spanning two months: the calculation is per calendar month, so if a stay splits across two months, the 21,000-yen test and the ceiling are judged in each month separately.
Also, the counter payment being capped at the ceiling via the Myna insurance card or a ceiling-amount certificate basically works per person, per medical institution. Family portions and amounts spread across multiple institutions under household aggregation are not processed automatically at the counter; as a rule, you get them back later by applying to your insurer (or via a notice from the insurer). If you do not know this, you will miss the aggregated portion.
Multiple-time reduction: three payouts in 12 months, and the ceiling drops from the fourth
If your household has received the high-cost medical care benefit three or more times in the 12 months up to and including the month of treatment, the "multiple-time" ceiling applies from the fourth time on. In bracket C that is 44,400 yen. The three months need not be consecutive — scattered months count as long as there are three within the most recent 12 months. A month in which household aggregation pushed you over the ceiling and triggered a payout also counts as one time.
Worked example: a bracket-C patient with ongoing monthly treatment (from August 2026)
Continuing treatment with monthly medical costs of 500,000 yen (30% at the counter = 150,000 yen):
- Months 1–3: 85,800 yen + (500,000 yen − 286,000 yen) × 1% = 87,940 yen
- From the 4th month: 44,400 yen (43,540 yen lighter per month)
- Over 12 months: 87,940 yen × 3 + 44,400 yen × 9 = about 663,000 yen (about 1,055,000 yen without the multiple-time reduction)
The biggest trap: changing insurers resets the count
The multiple-time count only accumulates payouts under the same insurer. If any of the following moves happens mid-treatment, the count starts over from zero.
| Type of move | What happens to the count |
|---|---|
| Job change from a health insurance society to Kyokai Kenpo (or vice versa, or to another society) | Reset (the insurer changes) |
| Leaving a job: company health insurance to NHI, or becoming a family member's dependent | Reset |
| Kyokai Kenpo both before and after the job change (remaining the insured person) | Carried over (same insurer) |
| Staying on NHI and moving within the same prefecture (with household continuity) | Carried over (since NHI moved to prefecture-level management in April 2018) |
| Staying on NHI but moving across prefectures | Reset |
If you are considering changing or leaving a job in the middle of long-term treatment, depending on the timing, a difference of over 40,000 yen a month can persist for several months. We compare post-retirement insurance options in the three health insurance choices after leaving a job — if you are in multiple-time status, add "does the insurer change?" to your decision criteria. The government also recognizes this reset problem as an issue: a Ministry of Health, Labour and Welfare expert committee stated in its December 2025 summary that work should proceed "toward realizing a mechanism whereby the count is carried over." It may improve in the future, but for now you must act on the assumption that the count resets.
For households burdened by both medical and long-term care costs, there is also an annual combined scheme, the high-cost medical/long-term care combined benefit. See also our guide to the high-cost long-term care service benefit and the annual combined scheme.
How to apply: where, how, and by when
- Apply to the insurer you are enrolled with. Company employees: your health insurance society or Kyokai Kenpo (prefectural branch); self-employed or retired: your municipality's NHI counter. The insurer's name is printed on your insurance card or eligibility confirmation certificate.
- Whether an application is needed depends on the insurer. Kyokai Kenpo requires submitting a high-cost medical care benefit claim form. Many municipalities send application notices to eligible NHI households, and some health insurance societies pay automatically into your salary account with no application. Do not assume "it should come back without doing anything" — check your insurer's method once.
- Payment takes three months or more from the month of treatment (waiting for medical claims data to be finalized). If you cannot pay urgent medical bills, there is also a high-cost medical expense loan program (Kyokai Kenpo and others) that lends 80–90% of the expected benefit interest-free.
- The claim deadline is two years. You can apply retroactively within two years counted from the first day of the month following the month of treatment. Amounts you missed because "I didn't know about aggregation" or "I didn't notice the multiple-time reduction" can be recovered if within the past two years. Use your medical expense notices or the medical cost data on Myna Portal to identify months that likely exceeded the ceiling.
What to do today
- Using Myna Portal or your medical expense notices, list the months in the past two years when a family member's out-of-pocket payment was 21,000 yen or more per bill (check whether any month exceeds the ceiling once aggregated)
- Count whether you have three or more high-cost benefit payouts (months over the ceiling) in the most recent 12 months. If so, ask your insurer whether the multiple-time ceiling applies from this month
- If you are in treatment and planning to change or leave your job, check whether the new insurer is the same as your current one (if it changes, the multiple-time count goes back to zero)
For more actions, see the take-home pay action list.
FAQ
Q. My spouse and I both work and have separate health insurance. Can we aggregate our medical costs as a household?
A. No. Household aggregation only applies among people enrolled with the same insurer (the insured person and their dependents; for NHI, members of the same household). Even with the same residence register, different insurance means no aggregation — each insurance judges the ceiling separately.
Q. Are payments under 21,000 yen completely wasted?
A. For household aggregation under the high-cost benefit, payments for people under 70 are excluded if under 21,000 yen per bill (payments for those 70 and over can be aggregated regardless of amount). However, they can still be included in the medical expense deduction on your tax return regardless of amount, so keep the receipts and statements.
Q. What happens to my multiple-time status when I change jobs?
A. If the insurer changes (from a health insurance society to Kyokai Kenpo, etc.), the count resets and you start from zero under the new insurance. If you are on Kyokai Kenpo both before and after (remaining the insured person), the count carries over. Between NHI plans, the count also carries over if you move within the same prefecture with household continuity.
Q. I just realized I forgot to aggregate in the past. Can I still claim it back?
A. Yes, within two years counted from the first day of the month following the month of treatment, you can apply retroactively to your insurer. Total up your family's out-of-pocket payments by month using medical expense notices or Myna Portal, and if any month exceeds the ceiling, apply to your insurer (health insurance society, Kyokai Kenpo, or the NHI counter).
References (sources)
* Ceilings and the annual cap are those for people under 70 as of August 2026 (after the revision effective for treatment from August 2026). Actual burdens vary with the brackets for those 70 and over, supplementary benefits from health insurance societies, and municipal medical cost subsidies. Always confirm your bracket, benefit amounts and application procedures with your insurer. This article is general information; for individual decisions, consult your insurer or a professional.