diff --git a/README.md b/README.md
index df64563..0546e34 100644
--- a/README.md
+++ b/README.md
@@ -40,6 +40,22 @@ memory-bank-cli --version
 
 See [CHANGELOG.md](CHANGELOG.md) for release notes.
 
+## Repair a missing ownership lock
+
+`doctor` is read-only by default. If it reports `template.identity_missing`,
+preview the same safe adoption plan used by `init` with pinned template
+provenance:
+
+```sh
+memory-bank-cli doctor --fix --dry-run \
+  --source <clean-template-checkout> \
+  --template-version <version> \
+  --source-ref <full-commit-sha>
+```
+
+Rerun without `--dry-run` to create `memory-bank/.lock`, then commit that lock
+before running `update`. The repair never replaces an existing lock.
+
 ## Upgrade
 
 Install the desired newer semantic version with the same command:
diff --git a/internal/cli/cli.go b/internal/cli/cli.go
index 261ee47..9e38b68 100644
--- a/internal/cli/cli.go
+++ b/internal/cli/cli.go
@@ -308,6 +308,11 @@ func runDoctor(arguments []string, stdout, stderr io.Writer) int {
 	profileArgument := flags.String("profile", "auto", "diagnostic profile: auto, template, or downstream")
 	scopeRootArgument := flags.String("scope-root", defaultScopeRoot, "repository-relative Memory Bank directory to diagnose")
 	maxDepth := flags.Int("max-depth", defaultMaxDepth, "maximum navigation depth before a warning")
+	fix := flags.Bool("fix", false, "repair supported findings (currently template.identity_missing)")
+	dryRun := flags.Bool("dry-run", false, "show the complete repair mutation plan without applying it (requires --fix)")
+	sourceRootArgument := flags.String("source", "", "clean template Git checkout containing template/ (legacy memory-bank-template/ or memory-bank/ is accepted for migration)")
+	templateVersion := flags.String("template-version", "", "human-readable template version for a repair")
+	sourceRef := flags.String("source-ref", "", "full commit SHA matching the repair source checkout HEAD")
 	jsonOutput := addJSONOutputFlag(flags)
 	if err := flags.Parse(arguments); err != nil {
 		if errors.Is(err, flag.ErrHelp) {
@@ -323,6 +328,19 @@ func runDoctor(arguments []string, stdout, stderr io.Writer) int {
 		fmt.Fprintln(stderr, "memory-bank-cli doctor: --max-depth must be greater than or equal to 0")
 		return exitUsage
 	}
+	explicitSource := *sourceRootArgument != "" || *templateVersion != "" || *sourceRef != ""
+	if explicitSource && (*sourceRootArgument == "" || *templateVersion == "" || *sourceRef == "") {
+		fmt.Fprintln(stderr, "memory-bank-cli doctor: --source, --template-version, and --source-ref must be provided together")
+		return exitUsage
+	}
+	if *dryRun && !*fix {
+		fmt.Fprintln(stderr, "memory-bank-cli doctor: --dry-run requires --fix")
+		return exitUsage
+	}
+	if explicitSource && !*fix {
+		fmt.Fprintln(stderr, "memory-bank-cli doctor: --source, --template-version, and --source-ref require --fix")
+		return exitUsage
+	}
 	profile, err := doctor.NormalizeProfile(*profileArgument)
 	if err != nil {
 		fmt.Fprintln(stderr, err)
@@ -353,6 +371,33 @@ func runDoctor(arguments []string, stdout, stderr io.Writer) int {
 		fmt.Fprintln(stderr, err)
 		return exitFailure
 	}
+	if *fix && hasDoctorFinding(report, "template.identity_missing") {
+		if !explicitSource {
+			fmt.Fprintln(stderr, "memory-bank-cli doctor --fix: template.identity_missing requires --source, --template-version, and --source-ref")
+			return exitUsage
+		}
+		sourceRoot, err := filepath.Abs(*sourceRootArgument)
+		if err != nil {
+			fmt.Fprintln(stderr, err)
+			return exitFailure
+		}
+		plan, err := ownership.Init(ownership.Options{RepoRoot: repoRoot, SourceRoot: sourceRoot, TemplateVersion: *templateVersion, SourceRef: *sourceRef, DryRun: *dryRun, AgentFile: *agentFile})
+		if err != nil {
+			fmt.Fprintln(stderr, err)
+			return exitFailure
+		}
+		markInitLockCreation(&plan)
+		report.Repair = &doctor.Repair{Finding: "template.identity_missing", Plan: plan}
+		if plan.Applied {
+			repaired, err := doctor.Run(doctor.Options{RepoRoot: repoRoot, ScopeRoot: scopeRoot, AgentFile: *agentFile, Profile: profile, MaxDepth: *maxDepth})
+			if err != nil {
+				fmt.Fprintln(stderr, err)
+				return exitFailure
+			}
+			repaired.Repair = report.Repair
+			report = repaired
+		}
+	}
 	if err := writeResult(stdout, *jsonOutput, report, func(writer io.Writer) { printDoctorReport(writer, report) }); err != nil {
 		fmt.Fprintln(stderr, err)
 		return exitFailure
@@ -363,6 +408,33 @@ func runDoctor(arguments []string, stdout, stderr io.Writer) int {
 	return exitSuccess
 }
 
+func hasDoctorFinding(report doctor.Report, code string) bool {
+	for _, finding := range report.Findings {
+		if finding.Code == code {
+			return true
+		}
+	}
+	return false
+}
+
+// markInitLockCreation gives the shared init plan its adoption-specific
+// presentation: init writes a previously absent lock, rather than updating one.
+func markInitLockCreation(plan *ownership.Report) {
+	for index := len(plan.Decisions) - 1; index >= 0; index-- {
+		if plan.Decisions[index].Path != ownership.LockFileName {
+			continue
+		}
+		plan.Decisions[index].Action = ownership.Create
+		plan.Decisions[index].Reason = "record successful adoption"
+		return
+	}
+	plan.Decisions = append(plan.Decisions, ownership.Decision{
+		Path:   ownership.LockFileName,
+		Action: ownership.Create,
+		Reason: "record successful adoption",
+	})
+}
+
 func printDoctorReport(writer io.Writer, report doctor.Report) {
 	fmt.Fprintf(writer, "Memory Bank doctor (%s profile)\n", report.Profile)
 	if report.TemplateIdentity.Version != "" {
@@ -376,6 +448,13 @@ func printDoctorReport(writer io.Writer, report doctor.Report) {
 		fmt.Fprintf(writer, "%s\t%s\t%s\t%s\n", finding.Severity, finding.Code, subject, finding.Message)
 		fmt.Fprintf(writer, "  remediation: %s\n", finding.Remediation)
 	}
+	if report.Repair != nil {
+		fmt.Fprintf(writer, "Repair plan for %s:\n", report.Repair.Finding)
+		printOwnershipReport(writer, report.Repair.Plan)
+		if report.Repair.Plan.Applied {
+			fmt.Fprintln(writer, "Repair completed: commit memory-bank/.lock before running update.")
+		}
+	}
 	fmt.Fprintf(writer, "Result: %d error(s), %d warning(s), %d info\n", report.Summary.Errors, report.Summary.Warnings, report.Summary.Info)
 }
 
diff --git a/internal/cli/cli_test.go b/internal/cli/cli_test.go
index ed788c5..7dce3c8 100644
--- a/internal/cli/cli_test.go
+++ b/internal/cli/cli_test.go
@@ -428,6 +428,137 @@ func TestDoctorAndAlternativeAgentTarget(t *testing.T) {
 	}
 }
 
+func TestDoctorFixAdoptsMissingLockWithExplicitProvenance(t *testing.T) {
+	repo, source := t.TempDir(), t.TempDir()
+	readme := "---\ndoc_function: index\npurpose: Test index for doctor.\nstatus: active\n---\n# Memory Bank\n"
+	if err := os.MkdirAll(filepath.Join(source, "memory-bank"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.MkdirAll(filepath.Join(repo, "memory-bank"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(source, "memory-bank", "README.md"), []byte(readme), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(repo, "memory-bank", "README.md"), []byte(readme), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	sourceRef := commitCLISource(t, source, "source")
+	base := []string{"doctor", "--fix", "--repo-root", repo, "--source", source, "--template-version", "v1", "--source-ref", sourceRef}
+
+	var stdout, stderr bytes.Buffer
+	if exitCode := Run(append(append([]string{}, base...), "--dry-run", "--json"), "test", &stdout, &stderr); exitCode != 1 {
+		t.Fatalf("dry-run exit = %d, stderr=%s", exitCode, stderr.String())
+	}
+	var dryRun struct {
+		Repair struct {
+			Finding string `json:"finding"`
+			Plan    struct {
+				DryRun    bool `json:"dry_run"`
+				Decisions []struct {
+					Path string `json:"path"`
+				} `json:"decisions"`
+			} `json:"plan"`
+		} `json:"repair"`
+	}
+	if err := json.Unmarshal(stdout.Bytes(), &dryRun); err != nil {
+		t.Fatalf("invalid dry-run report: %v\n%s", err, stdout.String())
+	}
+	if !strings.Contains(stdout.String(), "memory-bank-cli doctor --fix") {
+		t.Fatalf("missing-lock remediation does not guide the repair: %s", stdout.String())
+	}
+	if dryRun.Repair.Finding != "template.identity_missing" || !dryRun.Repair.Plan.DryRun || len(dryRun.Repair.Plan.Decisions) == 0 {
+		t.Fatalf("unexpected dry-run repair: %#v", dryRun)
+	}
+	lockPlanned := false
+	lockDecisionCount := 0
+	for _, decision := range dryRun.Repair.Plan.Decisions {
+		if decision.Path == "memory-bank/.lock" {
+			lockPlanned = true
+			lockDecisionCount++
+		}
+	}
+	if !lockPlanned {
+		t.Fatalf("dry-run omitted the lock creation: %#v", dryRun.Repair.Plan.Decisions)
+	}
+	if lockDecisionCount != 1 {
+		t.Fatalf("dry-run should contain one lock creation, got %d decisions: %#v", lockDecisionCount, dryRun.Repair.Plan.Decisions)
+	}
+	if _, err := os.Stat(filepath.Join(repo, "memory-bank", ".lock")); !os.IsNotExist(err) {
+		t.Fatalf("dry-run created a lock: %v", err)
+	}
+
+	stdout.Reset()
+	stderr.Reset()
+	if exitCode := Run(base, "test", &stdout, &stderr); exitCode != 0 {
+		t.Fatalf("repair exit = %d, stderr=%s", exitCode, stderr.String())
+	}
+	if !strings.Contains(stdout.String(), "commit memory-bank/.lock") {
+		t.Fatalf("repair did not recommend committing the lock: %s", stdout.String())
+	}
+	if !strings.Contains(stdout.String(), "create\t\tmemory-bank/.lock\trecord successful adoption") {
+		t.Fatalf("repair report omitted the lock creation: %s", stdout.String())
+	}
+	lock, err := os.ReadFile(filepath.Join(repo, "memory-bank", ".lock"))
+	if err != nil || !strings.Contains(string(lock), sourceRef) {
+		t.Fatalf("repair did not create the pinned lock: %q, %v", lock, err)
+	}
+
+	stdout.Reset()
+	stderr.Reset()
+	if exitCode := Run([]string{"doctor", "--fix", "--repo-root", repo, "--json"}, "test", &stdout, &stderr); exitCode != 0 {
+		t.Fatalf("repair with an existing lock failed: exit=%d stderr=%s", exitCode, stderr.String())
+	}
+	var existing struct {
+		Repair any `json:"repair"`
+	}
+	if err := json.Unmarshal(stdout.Bytes(), &existing); err != nil || existing.Repair != nil {
+		t.Fatalf("existing lock should not produce a repair: %#v, %v", existing, err)
+	}
+}
+
+func TestDoctorFixRequiresProvenanceAndPreservesConflictingManagedContent(t *testing.T) {
+	repo, source := t.TempDir(), t.TempDir()
+	readme := "---\ndoc_function: index\npurpose: Test index for doctor.\nstatus: active\n---\n# Memory Bank\n"
+	if err := os.MkdirAll(filepath.Join(source, "template", "memory-bank"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.MkdirAll(filepath.Join(repo, "memory-bank"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(source, "template", "memory-bank", "README.md"), []byte(readme), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(repo, "memory-bank", "README.md"), []byte("local customization\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	sourceRef := commitCLISource(t, source, "source")
+
+	var stdout, stderr bytes.Buffer
+	if exitCode := Run([]string{"doctor", "--fix", "--repo-root", repo}, "test", &stdout, &stderr); exitCode != exitUsage {
+		t.Fatalf("missing provenance exit = %d, stderr=%s", exitCode, stderr.String())
+	}
+	if !strings.Contains(stderr.String(), "requires --source, --template-version, and --source-ref") {
+		t.Fatalf("missing provenance error is not actionable: %s", stderr.String())
+	}
+
+	stdout.Reset()
+	stderr.Reset()
+	arguments := []string{"doctor", "--fix", "--repo-root", repo, "--source", source, "--template-version", "v1", "--source-ref", sourceRef, "--json"}
+	if exitCode := Run(arguments, "test", &stdout, &stderr); exitCode != exitFailure {
+		t.Fatalf("conflicting repair exit = %d, stderr=%s", exitCode, stderr.String())
+	}
+	if !strings.Contains(stdout.String(), "existing managed file does not match initialization source") {
+		t.Fatalf("conflicting managed content was not reported: %s", stdout.String())
+	}
+	if data, err := os.ReadFile(filepath.Join(repo, "memory-bank", "README.md")); err != nil || string(data) != "local customization\n" {
+		t.Fatalf("conflicting managed content changed: %q, %v", data, err)
+	}
+	if _, err := os.Stat(filepath.Join(repo, "memory-bank", ".lock")); !os.IsNotExist(err) {
+		t.Fatalf("conflicting repair created a lock: %v", err)
+	}
+}
+
 func TestDoctorRejectsUnknownProfile(t *testing.T) {
 	var stdout, stderr bytes.Buffer
 	if exitCode := Run([]string{"doctor", "--profile", "mystery"}, "test", &stdout, &stderr); exitCode != 2 {
diff --git a/internal/doctor/doctor.go b/internal/doctor/doctor.go
index 4f24f68..843f44a 100644
--- a/internal/doctor/doctor.go
+++ b/internal/doctor/doctor.go
@@ -122,7 +122,7 @@ func (report *Report) checkIdentityAndDrift(agentFile, scopeRoot string) {
 		agentContract, tracked := lock.Files[filepath.ToSlash(agentFile)]
 		templateOwnsAgentFile = tracked && agentContract.Ownership == ownership.Managed
 	} else if report.Profile == ProfileDownstream {
-		report.add(Finding{Code: "template.identity_missing", Severity: Error, Group: "template_identity", Path: ownership.LockFileName, Message: "The downstream repository has no ownership lock, so its installed template version is unknown.", Remediation: "Adopt the template with memory-bank-cli init and commit memory-bank/.lock."})
+		report.add(Finding{Code: "template.identity_missing", Severity: Error, Group: "template_identity", Path: ownership.LockFileName, Message: "The downstream repository has no ownership lock, so its installed template version is unknown.", Remediation: "Run memory-bank-cli doctor --fix with --source, --template-version, and --source-ref from a trusted template checkout, then commit memory-bank/.lock."})
 	} else {
 		report.add(Finding{Code: "template.source_repository", Severity: Info, Group: "template_identity", Subject: "template", Message: "Template source profile detected; an installed-template lock is not expected.", Remediation: "Create locks only in downstream repositories through memory-bank-cli init."})
 	}
diff --git a/internal/doctor/types.go b/internal/doctor/types.go
index 56884d8..9a77515 100644
--- a/internal/doctor/types.go
+++ b/internal/doctor/types.go
@@ -1,12 +1,14 @@
 // Package doctor diagnoses Memory Bank adoption and governance without mutation.
 package doctor
 
-import "github.com/dapi/memory-bank-cli/internal/lint"
+import (
+	"github.com/dapi/memory-bank-cli/internal/lint"
+	"github.com/dapi/memory-bank-cli/internal/ownership"
+)
 
-// ReportFormatVersion identifies the aggregate doctor JSON schema. Version 2
-// reflects the replacement of the former ownership-style drift/conflict fields
-// with the aggregate summary and findings contract.
-const ReportFormatVersion = 2
+// ReportFormatVersion identifies the aggregate doctor JSON schema. Version 3
+// adds the optional structured repair plan emitted by doctor --fix.
+const ReportFormatVersion = 3
 
 type Profile string
 
@@ -54,6 +56,14 @@ type Report struct {
 	Summary          Summary          `json:"summary"`
 	Findings         []Finding        `json:"findings"`
 	Navigation       lint.Report      `json:"navigation"`
+	Repair           *Repair          `json:"repair,omitempty"`
+}
+
+// Repair records the opt-in ownership operation performed for a finding. The
+// plan is the same validated adoption plan produced by memory-bank-cli init.
+type Repair struct {
+	Finding string           `json:"finding"`
+	Plan    ownership.Report `json:"plan"`
 }
 
 type Options struct {