Cardano Ratifies Plutus Cost Model Update, Enactment Set for June 18

Cardano ratified the governance action for the Mainnet Plutus Cost Model update on June 13, 2026. According to Intersect MBO, enactment is scheduled for June 18 at around 21:45 UTC. The protocol parameter change updates Plutus cost models for V1, V2 and V3, the parameter sets used to calculate execution units for smart contract transactions on Cardano.

Cardano Governance Approved the Update Plutus Cost Models Action

The governance action, titled “Update Plutus Cost Models,” was submitted as a protocol parameter change on Cardano mainnet. On CardanoScan, the action is marked as ratified under governance action ID gov_action1eqhnsdyf3exhp5mqt7sdjtl7xy69wqg8tvg854psns2jt72cra3qqrcnr8r.

CardanoScan shows five Constitutional Committee votes in favor, with no votes against and no abstentions. The DRep vote is listed with 3.94 billion stake in favor, equal to 68.61 percent support. SPOs were not eligible to vote on this type of parameter update action, which is also shown in the explorer data.

Ratification means the governance action received the required approval through Cardano’s on-chain governance process. Enactment is the separate step in which the approved parameter change is applied to the network. After enactment, the updated cost models become part of the mainnet parameters used by tools that estimate execution budgets, fees and Plutus script behavior.

Plutus V1, V2 and V3 Cost Models Receive New On-Chain Values

The Plutus Cost Model determines the part of a transaction fee that accounts for Plutus script execution. It assigns execution units through CPU and memory components, which are then used to calculate fees for transactions that use smart contracts.

Plutus V1 refers to the original version of Cardano’s smart contract scripting environment introduced with the Alonzo era. Plutus V2 expanded scripting capabilities through the Vasil upgrade, including features that enabled more efficient dApp designs. Plutus V3 is a newer iteration associated with the Conway era and later upgrades, with an expanded set of built-in functions and cost model parameters.

The on-chain governance action updates the full cost model arrays for plutusV1, plutusV2 and plutusV3. The announced materials highlighted changes related to equalsByteString across V1, V2 and V3, as well as the integer operations divideInteger, modInteger, quotientInteger and remainderInteger in V3. A public technical clarification in the Intersect thread also stated that the changes are not limited to CPU values and that there are additional V1 and V2 changes, including memory costs.

For developers, the authoritative source is the full set of new values recorded in the on-chain governance action and displayed through CardanoScan, Cexplorer, AdaStat and related tools. No official table comparing all previous and new values was published in the announcement, so teams that need a full technical comparison must compare the new on-chain arrays with the previously active ledger cost model definitions.

Developers Need to Retest ExUnits, Fees and Script Budgets

Intersect asked developers and dApp teams to test their setups on Preview and Preprod before enactment. The reminder applies to DeFi protocols, NFT infrastructure, wallet integrations, indexers, transaction builders and backend services that calculate fees, CPU, memory and collateral values before submitting transactions to mainnet.

The practical test for teams is to re-execute and re-estimate script costs using current dApp code, transaction builders and cost estimation libraries. The goal is to confirm that scripts still execute within expected ExUnits limits and that fee and collateral calculations remain aligned with the new mainnet cost model parameters.

If a wallet, dApp or transaction builder uses hardcoded or outdated cost model values, it can calculate an incorrect execution budget. After enactment, that may lead to failed transaction execution if the budget is too low, or unnecessarily high fee estimates if the tool calculates from old or inaccurate assumptions.

The Plutus Cost Model update is a separate protocol parameter change action, distinct from the Van Rossem hard fork governance process. It is part of the same technical readiness period for Protocol Version 11, as wallets, infrastructure providers, dApps and node operators prepare for ledger and Plutus changes. On June 18, the updated cost models for existing parameters are applied to mainnet, while newly introduced Plutus primitives become active only after hard fork activation.