40 CFR 93 — Air-Quality Conformity of Federal Actions

General-conformity analysis for basing and construction actions. 46 sections, full current text (eCFR edition 2026-07-15), each cross-linked to the AF pubs that cite it.

SectionTitleAF citations
93.100Purpose.
93.101Definitions.
93.102Applicability.
93.103Priority.
93.104Frequency of conformity determinations.
93.105Consultation.
93.106Content of transportation plans and timeframe of conformity determinations.
93.107Relationship of transportation plan and TIP conformity with the NEPA process.
93.108Fiscal constraints for transportation plans and TIPs.
93.109Criteria and procedures for determining conformity of transportation plans, programs, and projects: General.
93.110Criteria and procedures: Latest planning assumptions.
93.111Criteria and procedures: Latest emissions model.
93.112Criteria and procedures: Consultation.
93.113Criteria and procedures: Timely implementation of TCMs.
93.114Criteria and procedures: Currently conforming transportation plan and TIP.
93.115Criteria and procedures: Projects from a transportation plan and TIP.
93.116Criteria and procedures: Localized CO, PM10, and PM2.5 violations (hot-spots).
93.117Criteria and procedures: Compliance with PM10 and PM2.5 control measures.
93.118Criteria and procedures: Motor vehicle emissions budget.
93.119Criteria and procedures: Interim emissions in areas without motor vehicle emissions budgets.
93.120Consequences of control strategy implementation plan failures.
93.121Requirements for adoption or approval of projects by other recipients of funds designated under title 23 U.S.C. or the Federal Transit Laws.
93.122Procedures for determining regional transportation-related emissions.
93.123Procedures for determining localized CO, PM10, and PM2.5 concentrations (hot-spot analysis).
93.124Using the motor vehicle emissions budget in the applicable implementation plan (or implementation plan submission).
93.125Enforceability of design concept and scope and project-level mitigation and control measures.
93.126Exempt projects.
93.127Projects exempt from regional emissions analyses.
93.128Traffic signal synchronization projects.
93.129Special exemptions from conformity requirements for pilot program areas.
93.150Prohibition.
93.151State implementation plan (SIP) revision.
93.152Definitions.
93.153Applicability.4 × 1 pubs
93.154Federal agency conformity responsibility.4 × 1 pubs
93.155Reporting requirements.
93.156Public participation.
93.157Reevaluation of conformity.
93.158Criteria for determining conformity of general Federal actions.
93.159Procedures for conformity determinations of general Federal actions.
93.160Mitigation of air quality impacts.
93.161Conformity evaluation for Federal installations with facility-wide emission budgets.
93.162Emissions beyond the time period covered by the SIP.
93.163Timing of offsets and mitigation measures.
93.164Inter-precursor mitigation measures and offsets.
93.165Early emission reduction credit programs at Federal facilities and installation subject to Federal oversight.
Unofficial reference aid. Confirm against the current eCFR edition before citing in a finding.
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