Starting February 1, 2024, there will be a charge of $0.005 per hour for all public IPv4 addresses, regardless of whether they are attached to a service or not. The rising cost of acquiring a single public IPv4 address, which has increased by over 300% in the past 5 years, has led to this change. The goal is to encourage users to be more mindful of their use of public IPv4 addresses and to consider transitioning to IPv6. This charge applies to all AWS services and regions. The AWS Free Tier for EC2 will include 750 hours of public IPv4 address usage per month for the first 12 months, starting February 1, 2024.
https://aws.amazon.com/blogs/aws/new-aws-public-ipv4-address-charge-public-ip-insights/