Ethereum prepares to overhaul its state structure with a Partitioned Binary Tree

EIP-8297 has cleared a mainnet shadowfork test, with full deployment slated for Q4 2026 and no firm date yet Ethereum is getting ready to reorganize the data underneath it. The plan is EIP-8297, known as the Partitioned Binary Tree, or PBT. The goals are smaller state proofs and a path to state expiry without taking the network offline. The proposal recently passed a meaningful test. On October 29, 2026, PBT went live on a mainnet shadowfork called glamsterdam-pbt-1, run by ethPandaOps. What the Partitioned Binary Tree actually changes To understand the upgrade, start with Ethereum’s “state.” That is the full record of every account balance, every smart contract’s code, and every piece of data those contracts store. Today, Ethereum organizes that record using a hexary Merkle Patricia Trie, or MPT. EIP-8297 swaps that for a binary tree. Every branch splits in two, which makes the structure simpler to walk through and simpler to prove things about. The proposal also folds three separate categories into one structure. Account headers, contract storage, and contract code would all live in a single binary tree. The “partitioned” part refers to how keys get sorted. They are grouped into ...