diff --git a/CHANGELOG.md b/CHANGELOG.md
index 492915c..9049a02 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -81,6 +81,16 @@ Fixed:
   what the run checked to a statement of when it ran; the unstamped report is
   the default and the one people paste into issues.
 
+Changed:
+
+- Minimum supported Python raised from 3.11 to 3.12 (#72), closing CQ-01
+  directly against the standard's stated floor (Python 3.10 reaches EOL
+  October 2026) instead of via the declared deviation `docs/adr/0001` had
+  recorded since 2026-07-09. `docs/adr/0006-python-312-floor.md` supersedes
+  0001. `README.md` and `CONTRIBUTING.md` now say "Requires Python 3.12 or
+  newer"; CI's test matrix is `3.12`/`3.13` (3.11 dropped). Installed
+  releases are unaffected; this binds new installs, upgrades, and local dev.
+
 Added:
 
 - `TODS-E207` checks that `routes_supplement.txt`'s `route_color` and
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index ee78365..78a84ca 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -7,7 +7,7 @@ count.
 
 ## Setup
 
-Requires Python 3.11 or newer. Dependencies are locked with
+Requires Python 3.12 or newer. Dependencies are locked with
 [uv](https://docs.astral.sh/uv/); CI installs from `uv.lock` with
 `uv sync --frozen`, which also fails the build if the lockfile has drifted
 from `pyproject.toml` (CQ-09). Using uv locally keeps your environment
diff --git a/README.md b/README.md
index 2fca4e6..c69899c 100644
--- a/README.md
+++ b/README.md
@@ -34,7 +34,7 @@ runs locally in your browser; feed files are not uploaded.
 
 ## Install
 
-Requires Python 3.11 or newer.
+Requires Python 3.12 or newer.
 
 ```sh
 pipx install tods-validate
diff --git a/docs/CONFORMANCE-GAPS.md b/docs/CONFORMANCE-GAPS.md
index 22d1309..de21c81 100644
--- a/docs/CONFORMANCE-GAPS.md
+++ b/docs/CONFORMANCE-GAPS.md
@@ -76,9 +76,15 @@ runs `uv sync --frozen` (lockfile-drift check for free); `CODEOWNERS` added
 
 **Closed 2026-07-09:** the ADR log exists — `docs/adr/0000` (the practice)
 plus backfills 0001 (3.11 floor, closing **CQ-44/45**'s first item and, with
-the committed `.python-version` pinned to CI's 3.12 gate version, **CQ-01**),
-0002 (i18n N/A), 0003 (`editor/vscode` nesting, closing **CQ-26**),
-0004 (rules-as-registry), 0005 (uv/lockfile adoption).
+the committed `.python-version` pinned to CI's 3.12 gate version, **CQ-01**
+via a declared deviation), 0002 (i18n N/A), 0003 (`editor/vscode` nesting,
+closing **CQ-26**), 0004 (rules-as-registry), 0005 (uv/lockfile adoption).
+
+**Updated 2026-08-21:** `requires-python` raised to `>=3.12` (#72), closing
+**CQ-01** directly against the standard's stated floor instead of via a
+declared deviation. `docs/adr/0006-python-312-floor.md` supersedes 0001;
+0001 stays in the log as the record of why the deviation existed from
+2026-07-09 to 2026-08-21.
 
 **Still open:**
 - **CQ-27** — dev deps still live in `[project.optional-dependencies].dev`,
diff --git a/docs/adr/0001-python-311-floor.md b/docs/adr/0001-python-311-floor.md
index 752ea1f..50c8bc5 100644
--- a/docs/adr/0001-python-311-floor.md
+++ b/docs/adr/0001-python-311-floor.md
@@ -1,6 +1,6 @@
 # 0001 — Python floor stays at 3.11; dev interpreter pinned to CI's gate version
 
-- Status: accepted (backfilled 2026-07-09; decision in force since the first release)
+- Status: superseded by 0006 (2026-08-21; decision was in force 2026-07-09 to 2026-08-21)
 - Date: 2026-07-09
 
 ## Context
diff --git a/docs/adr/0006-python-312-floor.md b/docs/adr/0006-python-312-floor.md
new file mode 100644
index 0000000..91be057
--- /dev/null
+++ b/docs/adr/0006-python-312-floor.md
@@ -0,0 +1,58 @@
+# 0006 — Python floor raised to 3.12; supersedes 0001
+
+- Status: accepted (2026-08-21)
+- Date: 2026-08-21
+- Supersedes: 0001 (`docs/adr/0001-python-311-floor.md`)
+
+## Context
+
+0001 kept `requires-python = ">=3.11"` as a declared, justified deviation
+from `CODE-QUALITY-STANDARD.md`'s CQ-01 (which specifies `>=3.12`, 3.11
+allowed only "EOL-track... with a justified ADR"). 0001 named two triggers
+for revisiting that floor: a runtime dependency forcing it, or 3.11 leaving
+upstream support.
+
+Neither trigger has fired yet — CPython 3.11 security support runs to
+October 2027, and `uv.lock` on `main` still resolved for 3.11 as of #72's
+first review pass. What changed is CQ-01's own rationale: Python 3.10
+reaches EOL October 2026, and CQ-01 already treats `>=3.12` (not `>=3.11`)
+as the compliant floor, since 3.12 buys structural pattern matching and
+`tomllib` everywhere and removes the conditional-import branches an older
+floor keeps alive. #72 raised the floor to close that gap directly rather
+than continue carrying it as a declared deviation.
+
+A 2026-07-31 review of #72 (see the PR's review comments) blocked it as
+written: mechanically clean, but it reversed 0001 without a superseding
+ADR, without updating `README.md`/`CONTRIBUTING.md` (both still said
+"Requires Python 3.11 or newer"), and without a CHANGELOG entry, and it
+sequenced ahead of the then-held v0.9.0 release scope. The v0.9.0 hold has
+since resolved (v0.9.0 shipped 2026-08-16); this ADR and the accompanying
+doc/CHANGELOG updates close the three mechanical gaps the review named.
+
+## Decision
+
+- `requires-python = ">=3.12"` (landed in #72, merged 2026-08-21/22).
+  `.python-version`, ruff `target-version`, mypy `python_version`,
+  classifiers, and the CI test matrix (`3.12`, `3.13`) all agree with the
+  new floor; `3.11` was dropped from the matrix in the same PR.
+- This is a direct compliance with CQ-01's stated floor, not a new declared
+  deviation — 0001's "declared deviation" framing no longer applies, and
+  0001 is superseded rather than amended, so the record of why the
+  deviation existed for over a month stays intact.
+- `README.md` and `CONTRIBUTING.md` are updated to state "Requires Python
+  3.12 or newer" (they were left saying 3.11 when #72 merged; fixed here).
+  `CHANGELOG.md`'s Unreleased section gets a `Changed:` entry, since this is
+  a user-facing floor raise the same way 0001 said it should be if it ever
+  happened.
+
+## Consequences
+
+- Contributors and CI on Python 3.11 no longer install; 3.11 users on a
+  pinned `tods-validate` release are unaffected (the floor only binds new
+  installs/upgrades and local dev).
+- `docs/CONFORMANCE-GAPS.md`'s CQ-01 entry is updated: it previously
+  described CQ-01 as closed via 0001's declared deviation plus a
+  `.python-version` pinned ahead of the floor; it is now closed by the
+  floor itself matching the standard, with no deviation to declare.
+- If the floor needs to move again, follow 0001's own precedent: a new ADR,
+  not a silent `pyproject.toml` edit.