Announcement: AWS SAM CLI dropping Python 3.9 support on March 19, 2026

[roger-zhangg]

Starting March 19, 2026, AWS SAM CLI will no longer support Python 3.9 as a runtime for running SAM CLI itself.

Why?

Python 3.9 reached end-of-life on October 5, 2025. Since then, an increasing number of SAM CLI's dependencies have dropped Python 3.9 support, requiring us to maintain version-conditional pins across many packages. Continuing to support Python 3.9 adds significant maintenance burden and limits our ability to adopt newer dependency versions.

What does this mean for you?

• If you are running SAM CLI installed from SAM CLI installer, no action is needed.
• If you are running SAM CLI with Python 3.10 or later, no action is needed.
• If you are running SAM CLI with Python 3.9, please upgrade to Python 3.10+ before March 19, 2026.
• This change only affects the Python version used to run SAM CLI. SAM CLI will continue to support building and invoking Lambda functions that use the `python3.9` Lambda runtime.

Timeline

Date	Action
Feb 25, 2026	Announcement
March 19, 2026	Python 3.9 support removed from SAM CLI

Recommended action

Upgrade to Python 3.11 or later for the best experience. You can check your current Python version with:

python --version
# or
sam --info

If you have questions or concerns, please comment on this issue.