5/12 Calculation of taxes and insurance premiums after retirement / Schedule confirmation

As the title suggests, I have now gathered enough figures to perform a high-precision calculation.

The assumptions are:
・Retiring on May 31, 2026
・Have a wife and child
・My income will be zero from now on, wife works part-time moderately
・Join the voluntary continuation plan until March next year, then switch to National Health Insurance

1. Social Insurance

Since the insurance premiums would be ruinous if I switched to National Health Insurance, I will rely on the voluntary continuation plan from June until March of next year.
The voluntary continuation premium is about 74,000 yen/month; I will pay the June portion normally, and
for the 9 months from July to March 2027, I will pay in a lump sum via 'advance payment' (it seems there is a slight discount).
Therefore, the insurance premium payments for fiscal year 2026 will be,about 730,000 yen in June... ①

From April 2027, I will switch to National Health Insurance.
National Health Insurance premiums are also determined by the previous year's income, but unfortunately, since I have salary and bonus income from January to May 2026, the premiums will be somewhat high.
After calculating, it is approximately570,000 yen/year, which I will pay in a lump sum next July... ②

From 2028 onwards, since I plan to have no income, the insurance premiums will drop significantly to just under 20,000 yen per year for the household. Since this is almost zero, I will consider it negligible.

2. Resident Tax

Similarly, resident tax for 2025 income will be collected starting in June 2026. This can also be paid in four installments, but since I want to pay it all at once,I will pay about 600,000 yen in June 2026... ③
For 2027, there will also be a collection for the salary income earned in 2026 (salary + bonus from January to May), soI will pay about 60,000 yen in June 2027... ④ ← So cheap!

After that, since there is no income, the resident tax will be 0 yen.

3. National Pension

In the case of unemployment or retirement, you can receive an exemption for two years under a system called 'Special Exemption for Unemployment, etc.' This makes my National Pension premium 0 yen (exempt).
Also, my wife's National Pension is expected to be exempt (i.e., zero yen) because 'my income is zero' and her income is also low.
Even after the exemption period expires, since my income is expected to remain zero, the situation will not change, and I expect to remain exempt.

Therefore, to summarize,
1.3 million yen for ① and ③ in June and July 2026
600,000 yen for ② and ④ in June and July 2027
Total of about 2 million yenneeds to be taken into account for payments.

The stories you see on YouTube like'I was cornered by tax payments after retirement!'refer to these payments ① through ④.
In my case, I don't know how much my retirement allowance will be, but I hope it can cover this...
(I wonder when I'll find out the amount of the retirement allowance... I'll try Googling it.)

That is all for the report on what I did today.