Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock (LockA locked padlock) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Emergency

This is not the current EPA website. To navigate to the current EPA website, please go to www.epa.gov. This website is historical material reflecting the EPA website as it existed on January 19, 2025. This website is no longer updated and links to external websites and some internal pages may not work. More information »

    • Environmental Topics
    • Air
    • Bed Bugs
    • Cancer
    • Chemicals, Toxics, and Pesticide
    • Climate Change
    • Emergency Response
    • Environmental Information by Location
    • Environmental Justice
    • Greener Living
    • Health
    • Land, Waste, and Cleanup
    • Lead
    • Mold
    • Radon
    • Research
    • Science Topics
    • Water Topics
    • A-Z Topic Index
    • Laws & Regulations
    • By Business Sector
    • By Topic
    • Compliance
    • Enforcement
    • Laws and Executive Orders
    • Regulations
    • Report a Violation
    • Environmental Violations
    • Fraud, Waste or Abuse
    • About EPA
    • Our Mission and What We Do
    • Headquarters Offices
    • Regional Offices
    • Labs and Research Centers
    • Planning, Budget, and Results
    • Organization Chart
    • EPA History
    • Staff Directory

Breadcrumb

  1. Home
  2. Air Emissions Inventories

National Emissions Inventory Process - FAQ

National Emissions Inventory Process frequently asked questions.

  • What facilities are required to report to the NEI?
  • Where are the NAICS/SIC and SCC codes changes that have been implemented for the 2017NEI?
  • How often are the NEI data updated and how frequently are the data published?
  • How complete are the data in the National Emissions Inventory?
  • Are the GHGs in the National Emissions Inventory Complete?
  • Where is more information available about emissions estimation methods used by the EPA?
  • How are emissions trends compiled?
  • How do I determine what SCCs have changed between inventory years?

Air Emissions Inventories

  • Get Data
    • 2020 NEI
      • 2020 NEI Technical Support Document (TSD)
      • 2020 NEI Online Retrieval Tool
      • 2020 Supporting Data and Summaries
      • 2020 Plan
      • 2020 NEI and Trends Report
    • All Emissions Data
    • Air Pollutants Emissions Trends Data
    • Air Emissions Modeling
  • Report Data
    • 2023 NEI Documentation
    • CAERS
      • CAERS Login
      • CAERS User Guide
    • EIS
      • Emissions Inventory System (EIS) Gateway
      • EIS User's Manual and How To's
      • Emissions Inventory System (EIS) Bridge Tools
    • Air Emissions Reporting Requirement (AERR)
  • Other Resources
    • Frequent Questions
    • Training
    • Emissions Inventory Guidance
    • Conference
      • 2023 International Emissions Inventory Conference
    • Methods and Science
  • Emissions Inventory Listservs
  • Points of Contact
Contact Us About Air Emissions Inventories
Contact Us About Air Emissions Inventories to ask a question, provide feedback, or report a problem.
Last updated on May 29, 2024
  • Assistance
  • Ayuda
  • Arabic
  • Chinese (simplified)
  • Chinese (traditional)
  • Aide
  • Asistans
  • Korean
  • Assistência
  • Russian
  • Tulong
  • Vietnamese
United States Environmental Protection Agency

Discover.

  • Accessibility Statement
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshot
  • Grants
  • No FEAR Act Data
  • Plain Writing
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data
  • Inspector General
  • Jobs
  • Newsroom
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions

Follow.