Amazon RDS for PostgreSQL supports minor versions 15.5, 14.10, 13.13, 12.17, and 11.22

Amazon Relational Database Service (RDS) for PostgreSQL now supports the latest minor versions PostgreSQL 15.5, 14.10, 13.13, 12.17, and 11.22. We recommend that you upgrade to the latest minor versions to fix known security vulnerabilities in prior versions of PostgreSQL, and to benefit from the bug fixes, performance improvements, and new functionality added by the PostgreSQL community. With this release, RDS for PostgreSQL now supports pgactive extension starting with PostgreSQL major versions 11 and higher.

Source:: Amazon AWS