My Number and Municipal DX: Practical Steps to a Usable Digital Japan

どうも〜おかむーです！

• Japan's My Number card is finally being used more broadly, but uptake varies a lot by generation and service.
• Municipal DX is moving from pilots to scaled platforms, yet legacy systems and UX gaps remain the bottleneck.
• Focused policy fixes — better UX, shared platforms, clear metrics — could unlock big efficiency and service gains.

結論

My Number adoption is crossing key thresholds (health-insurance integration roughly 50% usage as of early 2026), but the true value depends on municipal DX: shared, secure, user-centered platforms that let citizens actually use digital services without pain. 要するに、カードの枚数だけ増やしても意味が薄い。使える仕組みと計測可能な改善が必要なんです。

Background: where we are now

真面目な話をすると、ここ数年、日本のデジタル化は「道具は揃いつつあるが、使いこなせていない」段階です。

• My Number (マイナンバーカード) dashboard run by the Digital Agency has switched metrics (from issuance to holders) and is updated monthly, showing an active effort at monitoring adoption trends (Digital Agency dashboard).
• The Ministry of Health's push to make My Number function as the health insurance card (“マイナ保険証”) has paid off: by Feb 2026, utilization reached about 1 in 2 people —これ、すごくないですか？（Nikkei）
• At the same time, the central government and MIC are pushing municipal DX playbooks, common systems,といった取り組みで地方自治体の業務効率化を図っています（Digital Agency / 総務省のDX資料）。

Current adoption and the generation gap

データを見ると分かるのは「利用の世代差」です。

• Younger people may be comfortable with smartphone-based login and digital services, while older cohorts often stick to physical interactions or are wary of online authentication.
• Health-insurance integration hitting ~50% masks these intra-population differences —地域や年齢で差が大きいんですよね。

Why this matters: if adoption is uneven, digital services can worsen inequality instead of improving access.

What's working (and why)

• Central dashboards and monthly updates create transparency and let policymakers adjust tactics quickly. Monitoring adoption by holder-count (not just issuance) is a better metric of real use.
• Bundling services (e.g., health insurance, My Portal login) increases utility and network effects: once the card is actually useful, people keep using it.
• Shared municipal DX initiatives reduce duplication and costs. Common information-system efforts enable smaller cities to run modern services without huge budgets.

Key challenges

ぶっちゃけ、課題は技術より運用とUXにあります。

• Legacy systems and fragmented procurement: many municipalities run different systems that don't interoperate.
• User experience: registration, card activation, and multi-factor flows still feel clunky to non-tech users.
• Trust and privacy concerns: identity systems need ironclad governance and clear communication.
• Human capacity: local governments often lack engineers and product managers to run continuous improvement.

Recommendations — practical, measurable steps

真面目に取り組むなら、ここを優先してほしいです！

Measure the right things

- Track "active holders" and service usage (e.g., % of citizens using My Number as health insurer, % using My Portal monthly).

Improve onboarding and UX

- Mobile-first activation, simplified identity proofing flows, and in-person fallback for seniors.

Build shared platforms and APIs

- Common authentication, data-sharing APIs, and procurement frameworks so municipalities can adopt without reinventing.

Invest in people

- Create regional digital teams that support clusters of municipalities (shared SRE, product management, security ops).

Strengthen governance and transparency

- Publish privacy impact assessments, incident-response plans, and anonymized usage metrics.

Engineering lens: specifics I care about

• Identity: robust, privacy-preserving attributes (selective disclosure) instead of broadcasting personal data. 要するに、最低限の情報で認証できる仕組みを。
• APIs: versioned, documented, and backwards-compatible — so municipal systems can evolve without breaking services.
• Observability: telemetry on API latency, login success rates, abandonment points in flows — measure where users drop off and fix that.

Case note: "write-less one-stop window"

Digital Agency's "書かないワンストップ窓口" initiative is exactly the kind of product thinking we need: reduce friction at the counter, integrate backend data, and free municipal staff for higher-value work. Scaling that requires common back-office components and strong devops support.

まとめ

• My Number is no longer just a card — it's an identity layer with growing real-world use (health-insurance integration ~50% is a milestone).
• The next frontier is municipal DX at scale: shared platforms, better UX, and measurable targets will determine whether digital public services actually help citizens.
• Policy should shift from issuing cards to operating services: measure usage, fix onboarding, and support local governments with shared tech and people.

おかむーから一言

起業家として、技術は正しく使えば社会をガラッと良くできると信じてます。テクノロジーで公共をアップデートするって、本気でやればワクワクする仕事ですよ！