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Clean Air Markets

Allowance Data

As part of EPA's cap and trade programs, the Clean Air Markets Division (CAMD) maintains data on allowance allocations, accounts, holdings, and transactions. These data, combined with collected emissions data, are used to determine compliance of regulated sources. CAMD provides the following resources for accessing and understanding its allowance data.



  • CAMD's Allowance Data Guide: A basic introduction to EPA's active and retired market-based programs offering context to how allowances are distributed, traded, and tracked. Additionally, this document may serve as a companion for exploring EPA’s allowance trading program data, all of which is publicly available in the Air Markets Program Data (AMPD) web application.


  • Air Markets Program Data (AMPD): a web-based application that allows you to create custom queries, view reports, and download allowance account, holdings, transaction, and compliance data.

  • SO2 Allowance Auction Results: downloadable tables from the annual Acid Rain Program SO2 Allowance auction from 1993-present.

Frequent Questions

How do I cite the Allowance Data?

CAMD suggests the following citation for its Allowance Data:

United States Environmental Protection Agency (EPA). “Air Markets Program Data.” Washington, DC: Office of Atmospheric Programs, Clean Air Markets Division. Available from EPA’s Air Markets Program Data web site: