This is a translation of the Japanese original. The Japanese version is authoritative; figures follow Japanese tax law.
In the medical care system for people aged 75 and over (後期高齢者医療制度), dividends and share sale gains held in a specified account (特定口座) will now count when premiums and the co-payment rate are decided. This comes from an amending act promulgated on 5 June 2026 (Act No. 31 of 2026). The start date will be set by Cabinet Order, and the legal deadline is 4 June 2031. The Ministry of Health, Labour and Welfare (MHLW) expects it to take effect about four to five years after promulgation, around 2030 to 2031[MHLW, outline of the amending act (in Japanese)].
On Tokyo's current rates, a single person with a ¥2.5 million pension and ¥1 million in dividends would see the premium rise from ¥152,900 to ¥254,300 a year. With a ¥1.8 million pension and ¥500,000 in dividends, the co-payment at the clinic would move from 10% to 20%. NISA accounts are excluded. If you keep an eye on a parent's brokerage account, check the amounts of dividends and sale gains too.
The short answer: dividends and sale gains in specified accounts will count for over-75 premiums and co-payments, probably from around 2030
| Item | Details |
|---|---|
| Legal basis | Act partially amending the Health Insurance Act and others (健康保険法等の一部を改正する法律, Act No. 31 of 2026, promulgated 5 June 2026) |
| From when | A date set by Cabinet Order, no later than 4 June 2031. MHLW expects about four to five years after promulgation |
| Who | Members of the over-75 system (in principle age 75 and over). National Health Insurance for people up to 74 is not covered this time |
| Income covered | Dividends and gains on listed shares, investment trust distributions and interest on specified bonds, where tax was withheld in a specified account and no return was filed |
| Not covered | Dividends and gains in NISA accounts, interest on bank deposits, and the value of savings or other assets themselves |
| What changes | Premiums (the income-based part and the reduction test) and the 10%, 20% or 30% co-payment test |
| Your paperwork | None. Financial institutions send the same reports they give the tax office to the regional association as well |
Sources: Article 9 and supplementary provisions Article 1 item 7 of the bill[House of Representatives, text of the bill (in Japanese)], promulgation date and act number[House of Representatives, progress of the bill (in Japanese)], income not covered[MHLW, fair reflection of financial income (in Japanese)].
The Cabinet approved the bill on 13 March 2026, and it passed on 29 May[MHLW, the medical insurance reform act has passed (in Japanese)]. The same act's changes to high-cost medical expenses began in August 2026, but the financial income part will only take effect several years from now.
From when: the legal deadline is 4 June 2031, and MHLW expects around 2030 to 2031
The start date has not been fixed. The act's supplementary provisions say "a date set by Cabinet Order within a period not exceeding five years from the day of promulgation".
It takes time because the systems of financial institutions, the national government and local authorities have to be newly connected. MHLW has set out the expected order of steps[MHLW, outline of the amending act, p.4 (in Japanese)].
- About two years to build the national database that collects the reports
- Then one year of reports is gathered, and income is fixed the following June
- It applies from the August switch of co-payment rates and premiums
MHLW also notes that "the schedule may slip for other reasons". The "around 2029 to 2030" seen in news reports is an early estimate; the primary source expects about four to five years after promulgation.
What counts is dividends and sale gains left unfiled in a specified account. NISA and bank interest are excluded
The income is picked up from reports that financial institutions already send to the tax office. The act names three kinds of report[House of Representatives, text of the bill, Article 9 (in Japanese)].
- Annual transaction report for specified accounts (特定口座年間取引報告書: gains and dividends in the account)
- Payment records for dividends on listed shares and similar
- Trust statements and nominee records for dividends on listed shares and similar
Newly counted
- Sale gains in a withholding specified account with no return filed
- Dividends on listed shares where no return is filed
- Distributions from investment trusts, exchange-traded funds and real estate investment trusts
- Interest on specified bonds
Not counted
- Dividends and gains in NISA accounts (tax-free)
- Interest on bank deposits (not in the reports)
- The value of savings, shares and other assets themselves
- Survivors' and disability pensions
Sources: MHLW, "Fair reflection of financial income in the over-75 system" and reference materials p.4[MHLW, reference materials (in Japanese)]. That deposit interest is excluded is this site's reading, since it is not in the act's list of reports.
You do not need to submit anything. MHLW says "the administrative burden on individuals will not increase". The duty falls on financial institutions; failing to report can be punished by up to one year in prison or a fine of up to ¥500,000.
Why it does not count today: choosing "no return needed" keeps the income from reaching the municipality
Premiums and co-payment rates are set from the municipality's resident tax income data. Dividends and gains for which no return is filed do not appear in that data.
For dividends on listed shares, 15.315% income tax and special reconstruction income tax plus 5% resident tax are withheld, and no return is needed however large the amount[National Tax Agency No.1330 (in Japanese)]. Gains in a withholding specified account are treated the same way[National Tax Agency No.1463 (in Japanese)].
| How dividends are handled | Tax | Premiums and co-pay today |
|---|---|---|
| No return (withholding is final) | Ends at about 20% | Not counted → counted after reform |
| Filed under aggregate taxation | Dividend credit available | Already counted |
| Filed under separate taxation | Can offset losses | Already counted |
That is why "not filing dividends keeps premiums down" has been standard household advice for older people. In the MHLW example, the same income leads to a 10% or 20% co-payment depending only on whether a return is filed.
It used to be possible to file for income tax but choose no return for resident tax. That option was abolished from fiscal 2024 resident tax (income for 2023), and resident tax now follows the income tax choice[Kita City, Tokyo (in Japanese)]. This reform goes a step further, counting the income even with no return filed. How to choose the tax treatment of dividends is covered in tax on dividends and the dividend credit, and loss offsetting in tax returns for shares and NISA.
How much premiums rise: about ¥100,000 a year on ¥1 million in dividends, about ¥80,000 on ¥500,000 (Tokyo estimate)
The over-75 premium is a flat per-capita charge plus an income-based charge. When dividends or gains are added to income, the income-based part rises, and people on low incomes can lose the reduction of the flat charge.
Flat ¥53,300 + (income − ¥430,000) × 9.88%
A child and childcare support levy (flat ¥1,300 plus 0.26% of income) is added on top. The caps are ¥850,000 for the medical part and ¥21,000 for the child part. Each is rounded down to the nearest ¥100.
- Today: income is the pension's ¥1.4 million only (¥2.5 million − ¥1.1 million public pension deduction)
- Medical ¥149,100 + child ¥3,800 = ¥152,900 a year
- After reform: income ¥2.4 million. Medical ¥247,900 + child ¥6,400 = ¥254,300 a year
- Difference ¥101,400 a year (about ¥8,450 a month), roughly 10% of the ¥1 million dividends
- Today: income ¥700,000, flat charge reduced by half. ¥54,600 a year
- After reform: income ¥1.2 million. The income used for the reduction test is ¥1.05 million, above the ¥1 million line for a 20% reduction, so no reduction
- Medical ¥129,300 + child ¥3,300 = ¥132,600 a year
- Difference ¥78,000 a year, about 16% of the ¥500,000 dividends
* Rough figures on Tokyo's fiscal 2026 rates, assuming the full dividend is added to income. Rates and the calculation after the reform will be set by Cabinet Order and the association's rules. The "today" figure in Example B matches the worked example in how the over-75 medical care system works.
Example B bears a larger share relative to the dividends because losing the reduction adds to the bill. People with smaller pensions and some dividends feel the biggest effect in percentage terms. Rates differ by prefecture, so check your area in the 47-prefecture ranking of over-75 premiums.
Some people will move from a 10% to a 20% co-payment: the lines are ¥280,000 of taxable income and ¥2 million of pension plus other income
The co-payment rate may also rise once dividends count as income. It is judged each year with 1 August as the reference date, using the previous year's income[Tokyo association, co-payment rates (in Japanese)].
| Co-payment | Test (insured members of the same household) |
|---|---|
| 30% | Someone has resident tax taxable income of ¥1.45 million or more. If income (収入) is under ¥3.83 million for one person or ¥5.2 million for two or more, an application brings it to 10% or 20% |
| 20% | Someone has taxable income of ¥280,000 to under ¥1.45 million, and pension income plus other total income is ¥2 million or more for one person or ¥3.2 million or more for two or more |
| 10% | Everyone's taxable income is under ¥280,000, or neither of the above applies |
- Example B: today, pension income of ¥1.8 million is below ¥2 million, so 10%. After reform, ¥1.8 million + ¥500,000 dividends = ¥2.3 million, taxable income ¥470,000, so 20%
- Example A: today, taxable income ¥670,000 and pension income ¥2.5 million, so 20%. After reform, taxable income ¥1.67 million falls in the 30% band
- Example A's income is ¥2.5 million pension + ¥1 million dividends = ¥3.5 million. That is under ¥3.83 million, so an application keeps it at 20%
MHLW's example is a husband with a ¥2.3 million pension and ¥500,000 in dividends, and a wife with an ¥830,000 basic pension. Without filing the dividends the husband pays 10% and a ¥118,928 annual premium; with filing, 20% and ¥169,978 (national average rates for fiscal 2024 and 2025)[MHLW, reference materials p.5 (in Japanese)]. After the reform, the latter applies whether or not a return is filed.
A higher co-payment rate also changes the monthly cap for high-cost medical expenses. For people who see doctors or stay in hospital often, the co-payment difference can outweigh the premium difference.
How not to read this, and cautions: details await Cabinet Orders, National Health Insurance is a separate matter, and people who already file see no change
What has been decided is only the mechanism for sending reports to the regional associations. The details of how the income is counted for premiums are still to come.
- The calculation is not fixed. The Medical Insurance Committee said the concrete method "will continue to be considered"[Social Security Council Medical Insurance Committee, summary of discussion (in Japanese)]. How losses and loss carry-forwards are treated awaits Cabinet and ministerial orders.
- National Health Insurance for people up to 74 is not covered this time. The committee listed it as a candidate but, mindful of standardising local government systems, decided to "start with the over-75 system". Extending it is a separate debate.
- People who file dividends under aggregate taxation see no change. Their income is already counted. Only those who leave the income unfiled are affected.
- Selling in a hurry could backfire. The sale gain itself may count as income in the year of sale. Decide whether to sell by your investment goals, not by premiums alone.
- The estimates use today's rates. Premium rates are revised every two years, and Tokyo's rates when the change starts may differ.
The committee broadly supported the idea of fair burden sharing. Others argued that "financial income of working-age people should also count" and "assets should be captured too", so the line may keep moving. For the overall picture of tax and premiums in retirement, see tax and premiums for people living on a pension.
What to check now: look at the parent's annual transaction report for the specified account
The start is some way off, but today's paperwork shows how big the effect will be. The annual transaction report that brokers send around January lists the year's sale gains and dividends.
Whether filing pays off has to be weighed with premiums as well as tax. The thinking is covered in aggregate versus separate taxation: which is better.
Frequently asked questions
What about a specified account without withholding, or a general account?
Gains in these accounts in principle require a tax return, and once filed they already count for premiums. The reform newly counts income where withholding ended the tax and no return was filed.
Summary
- For people aged 75 and over on Late-Stage Elderly Healthcare, dividends and capital gains from specified brokerage accounts will be counted when determining premiums and the co-payment rate. NISA and bank interest are excluded.
- The Ministry of Health, Labour and Welfare expects this to take effect around 2030-2031; the legal deadline is June 4, 2031.
- Tokyo's estimate: for a single person with a ¥2.5 million pension and ¥1 million in dividends, the annual premium would rise from ¥152,900 to ¥254,300.
- For a pension of ¥1.8 million plus ¥500,000 in dividends, the co-payment share would move from 10% to 20%.
- No action is needed from individuals now. In the meantime, check your dividend and capital gains amounts on your specified account's annual transaction report.
References (sources)
- MHLW, "The medical insurance reform act has passed" (in Japanese)
- MHLW, outline of the act amending the Health Insurance Act and others (in Japanese) - start dates and expected schedule
- MHLW, "Fair reflection of financial income in the over-75 system" (in Japanese) - NISA excluded
- MHLW, reference materials (in Japanese) - income counted and not counted, example of the filing gap
- Social Security Council Medical Insurance Committee, summary of discussion (25 December 2025, in Japanese)
- House of Representatives, text of the bill (in Japanese) - Article 9 and supplementary provisions Article 1 item 7
- House of Representatives, progress of the bill (in Japanese) - promulgated 5 June 2026, Act No. 31
- Tokyo Metropolitan Association of Medical Care for the Elderly, how premiums are set (in Japanese)
- Tokyo Metropolitan Association of Medical Care for the Elderly, co-payment rates (in Japanese)
- National Tax Agency Tax Answer No.1330, dividend income (in Japanese)
- National Tax Agency Tax Answer No.1463, tax on share transfers (in Japanese)
- Kita City, Tokyo, end of choosing a different method for resident tax (in Japanese)
* The estimates add the full dividend to income at Tokyo's fiscal 2026 rates. This article is general information. For your own case, check with your regional association, municipal office, tax office or a tax accountant.
