---
slug: "aws-lambda-dotnet9-end-of-support"
title: "AWS Lambda: .NET 9 container base image deprecation"
summary: "Deprecation date for the .NET 9 container base image on AWS Lambda: 10 Nov 2026. .NET 9 is a container-only runtime on Lambda. At deprecation, Lambda's responsibility for updating the base image ends."
cloud: "aws"
service: "AWS Lambda"
service_slug: "lambda"
category: "runtime"
type: "end_of_support"
announced_date: null
effective_date: "2026-11-10"
effective_precision: "day"
replacement: null
affected_versions: ["dotnet9"]
source_url: "https://docs.aws.amazon.com/lambda/latest/dg/lambda-runtimes.html"
extra_source_urls: ["https://endoflife.date/aws-lambda"]
vendor_ref: "dotnet9"
last_checked_at: "2026-11-14T04:00:38.232Z"
created_at: "2026-11-14T05:36:08.287Z"
updated_at: "2026-11-14T05:36:08.287Z"
url: "https://eolwatch.dev/items/aws-lambda-dotnet9-end-of-support"
short_url: "https://eolwatch.dev/i/f2"
markdown_url: "https://eolwatch.dev/items/aws-lambda-dotnet9-end-of-support.md"
json_url: "https://eolwatch.dev/items/aws-lambda-dotnet9-end-of-support.json"
source_note: null
---

# AWS Lambda: .NET 9 container base image deprecation

Deprecation date for the .NET 9 container base image on AWS Lambda: 10 Nov 2026. .NET 9 is a container-only runtime on Lambda. At deprecation, Lambda's responsibility for updating the base image ends.

- Effective date: 10 Nov 2026
- Cloud: [AWS](https://eolwatch.dev/cloud/aws.md)
- Service: [AWS Lambda](https://eolwatch.dev/services/aws/lambda.md)
- Type: End of support
- Category: [Runtime](https://eolwatch.dev/categories/runtimes.md)
- Affected versions: dotnet9
- Replacement: Not stated by vendor
- Announced: Not stated by vendor
- Official source: [docs.aws.amazon.com](https://docs.aws.amazon.com/lambda/latest/dg/lambda-runtimes.html)
- Last checked: 14 Nov 2026

## What breaks

The AWS Lambda supported runtimes table lists .NET 9 as ".NET 9 (container only)", and the AWS base images for .NET table lists a .NET 9 base image. Lambda's responsibility for updating the container base image ends at deprecation. Deprecation notifications are not available for functions that use container images. The customer is responsible for upgrading functions to use a supported runtime or base image.

## Who is affected

### Affected versions

- `dotnet9`

## What to do

1. Upgrade the function to a supported base image. AWS says to upgrade before the previous image is deprecated. The [AWS base images for .NET](https://docs.aws.amazon.com/lambda/latest/dg/csharp-image.html) table also lists a .NET 10 base image.
2. If you use your own Dockerfile, set the FROM property to the URI of the new base image. Use the same .NET version in the TargetFramework of the project file.
3. Create a new container image for the function: build the Docker image, upload it to Amazon ECR, and deploy it to the Lambda function. For a function defined as a container image, changing the runtime means creating a new container image.

## Replacement

Not stated by vendor.

## Sources

- [Official source](https://docs.aws.amazon.com/lambda/latest/dg/lambda-runtimes.html) (docs.aws.amazon.com, Official)
- [Additional source](https://endoflife.date/aws-lambda) (endoflife.date, Via endoflife.date)

Last checked against the first source in this list on 14 Nov 2026.

Page: https://eolwatch.dev/items/aws-lambda-dotnet9-end-of-support | JSON: https://eolwatch.dev/items/aws-lambda-dotnet9-end-of-support.json

The text on this page is drafted with AI assistance from the vendor's text, checked against the official source and approved by a person before it is published.