diff --git a/app/features/calendar/components/BracketProgressionSelector.tsx b/app/features/calendar/components/BracketProgressionSelector.tsx
index 8b86c5250..6e25809b2 100644
--- a/app/features/calendar/components/BracketProgressionSelector.tsx
+++ b/app/features/calendar/components/BracketProgressionSelector.tsx
@@ -23,10 +23,12 @@ export function BracketProgressionSelector({
 	initialBrackets,
 	isInvitationalTournament,
 	setErrored,
+	isTournamentInProgress,
 }: {
 	initialBrackets?: Progression.InputBracket[];
 	isInvitationalTournament: boolean;
 	setErrored: (errored: boolean) => void;
+	isTournamentInProgress: boolean;
 }) {
 	const [brackets, setBrackets] = React.useState<Progression.InputBracket[]>(
 		initialBrackets ?? [defaultBracket()],
@@ -106,6 +108,7 @@ export function BracketProgressionSelector({
 						}
 						count={i + 1}
 						isInvitationalTournament={isInvitationalTournament}
+						isTournamentInProgress={isTournamentInProgress}
 					/>
 				))}
 			</div>
@@ -132,6 +135,7 @@ function TournamentFormatBracketSelector({
 	onDelete,
 	count,
 	isInvitationalTournament,
+	isTournamentInProgress,
 }: {
 	bracket: Progression.InputBracket;
 	brackets: Progression.InputBracket[];
@@ -139,6 +143,7 @@ function TournamentFormatBracketSelector({
 	onDelete?: () => void;
 	count: number;
 	isInvitationalTournament: boolean;
+	isTournamentInProgress: boolean;
 }) {
 	const id = React.useId();
 
@@ -353,7 +358,7 @@ function TournamentFormatBracketSelector({
 										startTime: undefined,
 									})
 								}
-								disabled={bracket.disabled}
+								disabled={bracket.disabled || isTournamentInProgress}
 							/>
 							<Label htmlFor={createId("follow-up-bracket")} spaced={false}>
 								Is follow-up bracket
diff --git a/app/features/calendar/routes/calendar.new.tsx b/app/features/calendar/routes/calendar.new.tsx
index d1195df6d..ea2d1a3e1 100644
--- a/app/features/calendar/routes/calendar.new.tsx
+++ b/app/features/calendar/routes/calendar.new.tsx
@@ -273,6 +273,7 @@ function EventForm() {
 						}
 						isInvitationalTournament={isInvitational}
 						setErrored={setBracketProgressionErrored}
+						isTournamentInProgress={false}
 					/>
 				</div>
 			) : null}
diff --git a/app/features/tournament/routes/to.$id.admin.tsx b/app/features/tournament/routes/to.$id.admin.tsx
index a5cf14dc5..403517183 100644
--- a/app/features/tournament/routes/to.$id.admin.tsx
+++ b/app/features/tournament/routes/to.$id.admin.tsx
@@ -815,6 +815,7 @@ function BracketProgressionEditDialog({ close }: { close: () => void }) {
 					}))}
 					isInvitationalTournament={tournament.isInvitational}
 					setErrored={setBracketProgressionErrored}
+					isTournamentInProgress
 				/>
 				<div className="stack md horizontal justify-center mt-6">
 					<SubmitButton