diff --git a/CHANGELOG.md b/CHANGELOG.md
index 48e9ded1e..9ed3c6e49 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Fixed
 - Fix regression from `v26.2.0` that caused channel logo watermarks to be ignored when the logo is a url
   - This affected external logo urls and generated channel logos
+- Return a retry response instead of `404` when an HLS segmenter playlist is temporarily unavailable
+  - Previously, a client that requested the playlist before the session had written it was told the stream did not exist
 
 ## [26.7.0] - 2026-07-27
 ### Added
diff --git a/ErsatzTV.Tests/Controllers/IptvControllerTests.cs b/ErsatzTV.Tests/Controllers/IptvControllerTests.cs
new file mode 100644
index 000000000..172f4eb1d
--- /dev/null
+++ b/ErsatzTV.Tests/Controllers/IptvControllerTests.cs
@@ -0,0 +1,86 @@
+using ErsatzTV.Controllers;
+using ErsatzTV.Core.FFmpeg;
+using LanguageExt;
+using ErsatzTV.Core.Interfaces.FFmpeg;
+using ErsatzTV.Core.Interfaces.Streaming;
+using MediatR;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Logging.Abstractions;
+using NSubstitute;
+using NUnit.Framework;
+using Shouldly;
+
+namespace ErsatzTV.Tests.Controllers;
+
+[TestFixture]
+public class IptvControllerTests
+{
+    private const string ChannelNumber = "1";
+
+    [Test]
+    public async Task GetLivePlaylist_Should_Return_Playlist_When_Trim_Succeeds()
+    {
+        var trimResult = new TrimPlaylistResult(DateTimeOffset.Now, 0, 0, "#EXTM3U", 1);
+        IptvController controller = MakeController(WorkerReturning(trimResult));
+
+        IActionResult result = await controller.GetLivePlaylist(ChannelNumber, CancellationToken.None);
+
+        var content = result.ShouldBeOfType<ContentResult>();
+        content.Content.ShouldBe("#EXTM3U");
+        content.ContentType.ShouldBe("application/vnd.apple.mpegurl");
+    }
+
+    [Test]
+    public async Task GetLivePlaylist_Should_Ask_Client_To_Retry_When_Trim_Fails()
+    {
+        IptvController controller = MakeController(WorkerReturning(Option<TrimPlaylistResult>.None));
+
+        IActionResult result = await controller.GetLivePlaylist(ChannelNumber, CancellationToken.None);
+
+        // the session worker exists, so the failure is transient; a 404 would tell clients the
+        // stream is gone and many would abandon it instead of polling again
+        var statusCode = result.ShouldBeOfType<StatusCodeResult>();
+        statusCode.StatusCode.ShouldBe(StatusCodes.Status503ServiceUnavailable);
+        controller.Response.Headers.RetryAfter.ToString().ShouldBe("1");
+    }
+
+    [Test]
+    public async Task GetLivePlaylist_Should_Redirect_To_Start_Session_When_No_Worker()
+    {
+        var segmenterService = Substitute.For<IFFmpegSegmenterService>();
+        segmenterService.TryGetWorker(Arg.Any<string>(), out Arg.Any<IHlsSessionWorker>()).Returns(false);
+
+        IActionResult result = await MakeController(segmenterService)
+            .GetLivePlaylist(ChannelNumber, CancellationToken.None);
+
+        result.ShouldBeOfType<RedirectToActionResult>()
+            .ActionName.ShouldBe(nameof(IptvController.GetHttpLiveStreamingVideo));
+    }
+
+    private static IFFmpegSegmenterService WorkerReturning(Option<TrimPlaylistResult> trimResult)
+    {
+        var worker = Substitute.For<IHlsSessionWorker>();
+        worker.TrimPlaylist(Arg.Any<DateTimeOffset>(), Arg.Any<CancellationToken>()).Returns(trimResult);
+
+        var segmenterService = Substitute.For<IFFmpegSegmenterService>();
+        segmenterService.TryGetWorker(Arg.Any<string>(), out Arg.Any<IHlsSessionWorker>())
+            .Returns(call =>
+            {
+                call[1] = worker;
+                return true;
+            });
+
+        return segmenterService;
+    }
+
+    private static IptvController MakeController(IFFmpegSegmenterService segmenterService) =>
+        new(
+            Substitute.For<IMediator>(),
+            Substitute.For<IGraphicsEngine>(),
+            NullLogger<IptvController>.Instance,
+            segmenterService)
+        {
+            ControllerContext = new ControllerContext { HttpContext = new DefaultHttpContext() }
+        };
+}
diff --git a/ErsatzTV.Tests/ErsatzTV.Tests.csproj b/ErsatzTV.Tests/ErsatzTV.Tests.csproj
index c7c4506c2..b233f5333 100644
--- a/ErsatzTV.Tests/ErsatzTV.Tests.csproj
+++ b/ErsatzTV.Tests/ErsatzTV.Tests.csproj
@@ -13,6 +13,7 @@
 
     <ItemGroup>
       <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.8.1" />
+      <PackageReference Include="NSubstitute" Version="6.0.0" />
       <PackageReference Include="NUnit" Version="4.6.1" />
       <PackageReference Include="NUnit.Analyzers" Version="4.14.0">
         <PrivateAssets>all</PrivateAssets>
diff --git a/ErsatzTV/Controllers/IptvController.cs b/ErsatzTV/Controllers/IptvController.cs
index bafd14ec4..c4823a8dd 100644
--- a/ErsatzTV/Controllers/IptvController.cs
+++ b/ErsatzTV/Controllers/IptvController.cs
@@ -170,9 +170,22 @@ public class IptvController : StreamingControllerBase
                 return Content(result.Playlist, "application/vnd.apple.mpegurl");
             }
 
-            // TODO: better error here?
-            _logger.LogWarning("Trim playlist failure; will return not found for channel {Channel}", channelNumber);
-            return NotFound();
+            // the session worker exists, so this is transient: either ffmpeg hasn't written the
+            // first playlist yet, or the read failed. 404 tells clients the stream is gone and
+            // many will abandon it, so ask them to retry shortly instead.
+            if (cancellationToken.IsCancellationRequested)
+            {
+                _logger.LogDebug("Trim playlist was canceled for channel {Channel}", channelNumber);
+            }
+            else
+            {
+                _logger.LogWarning(
+                    "Trim playlist failure for channel {Channel}; will ask client to retry",
+                    channelNumber);
+            }
+
+            Response.Headers.RetryAfter = "1";
+            return StatusCode(StatusCodes.Status503ServiceUnavailable);
         }
 
         _logger.LogWarning(