diff --git a/runatlantis.io/docs/using-atlantis.md b/runatlantis.io/docs/using-atlantis.md
index 24a0a29352..0311fa9e81 100644
--- a/runatlantis.io/docs/using-atlantis.md
+++ b/runatlantis.io/docs/using-atlantis.md
@@ -45,6 +45,10 @@ atlantis plan -w staging
 * `-w workspace` Switch to this [Terraform workspace](https://www.terraform.io/docs/state/workspaces.html) before planning. Defaults to `default`. If not using Terraform workspaces you can ignore this.
 * `--verbose` Append Atlantis log to comment.
 
+::: warning NOTE
+An `atlantis plan` (without flags), like autoplans, discards all plans previously created with `atlantis plan` `-p`/`-d`/`-w`
+:::
+
 ### Additional Terraform flags
 
 If you need to run `terraform plan` with additional arguments, like `-target=resource` or `-var 'foo-bar'` or `-var-file myfile.tfvars`
@@ -65,6 +69,7 @@ Runs `terraform apply` for the plan that matches the directory/project/workspace
 
 ::: tip
 If no directory/project/workspace is specified, ex. `atlantis apply`, this command will apply **all unapplied plans from this pull request**.
+This includes all projects that have been planned manually with `atlantis plan` `-p`/`-d`/`-w` since the last autoplan or `atlantis plan` command.
 :::
 
 ### Examples
diff --git a/server/events/command_runner_test.go b/server/events/command_runner_test.go
index 1254e96d03..a25603d874 100644
--- a/server/events/command_runner_test.go
+++ b/server/events/command_runner_test.go
@@ -431,9 +431,72 @@ func TestRunUnlockCommandFail_VCSComment(t *testing.T) {
 	vcsClient.VerifyWasCalledOnce().CreateComment(fixtures.GithubRepo, fixtures.Pull.Num, "Failed to delete PR locks", "unlock")
 }
 
+func TestRunAutoplanCommand_DeletePlans(t *testing.T) {
+	setup(t)
+	tmp, cleanup := TempDir(t)
+	defer cleanup()
+	boltDB, err := db.New(tmp)
+	Ok(t, err)
+	dbUpdater.DB = boltDB
+	applyCommandRunner.DB = boltDB
+	autoMerger.GlobalAutomerge = true
+	defer func() { autoMerger.GlobalAutomerge = false }()
+
+	When(projectCommandBuilder.BuildAutoplanCommands(matchers.AnyPtrToEventsCommandContext())).
+		ThenReturn([]models.ProjectCommandContext{
+			{
+				CommandName: models.PlanCommand,
+			},
+			{
+				CommandName: models.PlanCommand,
+			},
+		}, nil)
+	When(projectCommandRunner.Plan(matchers.AnyModelsProjectCommandContext())).ThenReturn(models.ProjectResult{PlanSuccess: &models.PlanSuccess{}})
+	When(workingDir.GetPullDir(matchers.AnyModelsRepo(), matchers.AnyModelsPullRequest())).ThenReturn(tmp, nil)
+	fixtures.Pull.BaseRepo = fixtures.GithubRepo
+	ch.RunAutoplanCommand(fixtures.GithubRepo, fixtures.GithubRepo, fixtures.Pull, fixtures.User)
+	pendingPlanFinder.VerifyWasCalledOnce().DeletePlans(tmp)
+}
+
+func TestRunGenericPlanCommand_DeletePlans(t *testing.T) {
+	setup(t)
+	tmp, cleanup := TempDir(t)
+	defer cleanup()
+	boltDB, err := db.New(tmp)
+	Ok(t, err)
+	dbUpdater.DB = boltDB
+	applyCommandRunner.DB = boltDB
+	autoMerger.GlobalAutomerge = true
+	defer func() { autoMerger.GlobalAutomerge = false }()
+
+	When(projectCommandRunner.Plan(matchers.AnyModelsProjectCommandContext())).ThenReturn(models.ProjectResult{PlanSuccess: &models.PlanSuccess{}})
+	When(workingDir.GetPullDir(matchers.AnyModelsRepo(), matchers.AnyModelsPullRequest())).ThenReturn(tmp, nil)
+	fixtures.Pull.BaseRepo = fixtures.GithubRepo
+	ch.RunCommentCommand(fixtures.GithubRepo, nil, nil, fixtures.User, fixtures.Pull.Num, &events.CommentCommand{Name: models.PlanCommand})
+	pendingPlanFinder.VerifyWasCalledOnce().DeletePlans(tmp)
+}
+
+func TestRunSpecificPlanCommandDoesnt_DeletePlans(t *testing.T) {
+	setup(t)
+	tmp, cleanup := TempDir(t)
+	defer cleanup()
+	boltDB, err := db.New(tmp)
+	Ok(t, err)
+	dbUpdater.DB = boltDB
+	applyCommandRunner.DB = boltDB
+	autoMerger.GlobalAutomerge = true
+	defer func() { autoMerger.GlobalAutomerge = false }()
+
+	When(projectCommandRunner.Plan(matchers.AnyModelsProjectCommandContext())).ThenReturn(models.ProjectResult{PlanSuccess: &models.PlanSuccess{}})
+	When(workingDir.GetPullDir(matchers.AnyModelsRepo(), matchers.AnyModelsPullRequest())).ThenReturn(tmp, nil)
+	fixtures.Pull.BaseRepo = fixtures.GithubRepo
+	ch.RunCommentCommand(fixtures.GithubRepo, nil, nil, fixtures.User, fixtures.Pull.Num, &events.CommentCommand{Name: models.PlanCommand, ProjectName: "default"})
+	pendingPlanFinder.VerifyWasCalled(Never()).DeletePlans(tmp)
+}
+
 // Test that if one plan fails and we are using automerge, that
 // we delete the plans.
-func TestRunAutoplanCommand_DeletePlans(t *testing.T) {
+func TestRunAutoplanCommandWithError_DeletePlans(t *testing.T) {
 	setup(t)
 	tmp, cleanup := TempDir(t)
 	defer cleanup()
@@ -476,7 +539,8 @@ func TestRunAutoplanCommand_DeletePlans(t *testing.T) {
 		ThenReturn(tmp, nil)
 	fixtures.Pull.BaseRepo = fixtures.GithubRepo
 	ch.RunAutoplanCommand(fixtures.GithubRepo, fixtures.GithubRepo, fixtures.Pull, fixtures.User)
-	pendingPlanFinder.VerifyWasCalledOnce().DeletePlans(tmp)
+	// gets called twice: the first time before the plan starts, the second time after the plan errors
+	pendingPlanFinder.VerifyWasCalled(Times(2)).DeletePlans(tmp)
 }
 
 func TestFailedApprovalCreatesFailedStatusUpdate(t *testing.T) {
diff --git a/server/events/plan_command_runner.go b/server/events/plan_command_runner.go
index 36fcb2253d..f3e6f59f37 100644
--- a/server/events/plan_command_runner.go
+++ b/server/events/plan_command_runner.go
@@ -105,6 +105,10 @@ func (p *PlanCommandRunner) runAutoplan(ctx *CommandContext) {
 		ctx.Log.Warn("unable to update commit status: %s", err)
 	}
 
+	// discard previous plans that might not be relevant anymore
+	ctx.Log.Debug("deleting previous plans")
+	p.deletePlans(ctx)
+
 	// Only run commands in parallel if enabled
 	var result CommandResult
 	if p.isParallelEnabled(projectCmds) {
@@ -179,6 +183,13 @@ func (p *PlanCommandRunner) run(ctx *CommandContext, cmd *CommentCommand) {
 
 	projectCmds, policyCheckCmds := p.partitionProjectCmds(ctx, projectCmds)
 
+	// if the plan is generic, new plans will be generated based on changes
+	// discard previous plans that might not be relevant anymore
+	if !cmd.IsForSpecificProject() {
+		ctx.Log.Debug("deleting previous plans")
+		p.deletePlans(ctx)
+	}
+
 	// Only run commands in parallel if enabled
 	var result CommandResult
 	if p.isParallelEnabled(projectCmds) {