Learn how to save PSD files for older versions of Photoshop with all currently supported versions of Adobe Photoshop for Creative Cloud on Windows and macOS.
How to Save PSD File for Older Version of Photoshop CC in MAC 2019
Set the default option in Photoshop preferences, called Maximize PSD and PSB File Compatibility (under the Edit > Preferences > File Handling menu). This setting is permanent, so you only need to set it once.
Make sure the area at the bottom of the File Compatibility area is set to Always or Ask. However, enabling this option will result in larger file sizes. If you only need this feature occasionally, set it to Ask. This way, Photoshop will ask you if you want to maximize compatibility each time you save a file. When this compatibility option is called, the layers are saved along with a flattened composition of the image.
When you open a newer Photoshop PSD file in an older Photoshop version, the new Photoshop features are not carried over when the file is opened in a version that does not contain those features. If the file is edited and saved in the older version, the unsupported features are removed.
