A Section 106 Memorandum of Agreement (MOA) and a Programmatic Agreement (PA) can both establish enforceable commitments for completing federal historic-preservation review, but they aren't interchangeable labels. An MOA is the agreement document ordinarily used under 36 CFR 800.6 to resolve adverse effects for a particular federal undertaking. A PA is a program alternative authorized by 36 CFR 800.14(b). It can govern an agency program, repetitive or multi-state undertakings, routine management activities, or a complex project when effects can't reasonably be fully identified before approval.
That distinction matters commercially. A draft MOA can show that consultation has reached the adverse-effect resolution stage and can expose proposed mitigation, documentation, design changes, monitoring, or treatment commitments. A PA can reveal something broader: the rules that will govern a long-running program or a complex undertaking, including which future activities receive streamlined review and which still require consultation.
Where MOAs fit in the standard Section 106 process
Section 106 requires a federal agency to take into account the effects of its undertakings on historic properties and give the Advisory Council on Historic Preservation (ACHP) a reasonable opportunity to comment. Under the standard process in 36 CFR Part 800, the agency initiates review, identifies historic properties, assesses effects, and, when there is an adverse effect, consults to avoid, minimize, or mitigate it. For a broader walkthrough, see Preserve Signal's guide to what Section 106 can signal about upcoming preservation work.
If the agency and the appropriate State Historic Preservation Officer (SHPO), or a Tribal Historic Preservation Officer (THPO) acting in the SHPO role for tribal lands within the tribe's jurisdiction, agree on how adverse effects will be resolved, 36 CFR 800.6 provides for an MOA. The ACHP is a signatory when it participates in the adverse-effect consultation. For historic properties of religious and cultural significance located off tribal lands, affected Indian tribes remain consulting parties and may be invited signatories; the SHPO does not simply drop out of the process. Once properly executed and implemented, the MOA evidences the agency's compliance with Section 106 and governs the undertaking and all of its parts.
An MOA therefore usually tells you that the review has moved beyond simply asking whether historic properties may be affected. The parties are documenting how identified adverse effects will be addressed.
What a Section 106 Memorandum of Agreement can contain
The exact stipulations are project-specific. An MOA might require design revisions, archaeological work, documentation, treatment plans, construction monitoring, interpretation, preservation of particular features, curation, reporting, or other measures developed through consultation. The agreement may also address later discoveries, duration, amendments, dispute resolution, and termination.
The agreement should be read carefully rather than treated as a generic 'mitigation agreement.' Avoidance and minimization can be part of the negotiated resolution too, and a mitigation commitment doesn't necessarily mean physical restoration work will follow.
The signature pages also matter. Under the regulations, signatories and invited signatories have different rights from concurring parties. Concurring parties can show agreement with the document but don't gain the signatories' authority to amend or terminate it merely by concurring. An entity assigned substantive implementation responsibilities should generally be made an invited signatory rather than only a concurring party.
When a Programmatic Agreement is different
A Section 106 Programmatic Agreement is one of the program alternatives in 36 CFR 800.14. The regulations allow a PA when effects are similar and repetitive or regional or multi-state in scope; when effects can't be fully determined before approval; when nonfederal parties receive major decision-making responsibilities; for routine management at federal installations or land-management units; or when other circumstances warrant departing from the normal Section 106 process. For an agency-program PA under § 800.14(b)(2), the agreement takes effect when executed by the ACHP, the agency official, and the appropriate SHPOs/THPOs, or NCSHPO's president when applicable. That is a higher ACHP execution threshold than a standard MOA in which the ACHP has not joined consultation. A separate exception exists for subsequent agreements using an ACHP-designated prototype PA under § 800.14(b)(4), which can become final without further ACHP participation or signature.
A program PA can establish a tailored Section 106 process for a category or agency program. Recurring transportation, grant, facility-management, or disaster-recovery activities may be handled through agreed procedures rather than recreating the same review structure for every action.
A project PA can apply to a particular complex undertaking. ACHP guidance identifies this as useful when completing the ordinary Section 106 process before a final decision isn't practical, such as when the agency can't yet fully determine the location, significance, or effects on historic properties. But phased survey work does not automatically require a PA. Section 800.4(b)(2) directly permits phased identification and evaluation for corridors or large land areas, or where access is restricted, and it also allows final identification and evaluation to be deferred when specifically provided for in an MOA, PA, or qualifying NEPA documentation. A project PA becomes especially useful when the agency needs an agreed framework for carrying unresolved identification, effects analysis, and adverse-effect resolution forward after the normal pre-approval review cannot practicably be completed.
So a PA isn't necessarily broader than a single project, and 'phased identification' isn't synonymous with 'project PA.' The regulations also recognize prototype PAs designated by the ACHP. Those can be used for the same type of program or undertaking in more than one case or area under the conditions of the prototype.
MOA vs. PA: the practical distinction
- Regulatory home. MOA: 36 CFR 800.6. PA: 36 CFR 800.14(b).
- Typical use. MOA: resolve adverse effects for a particular undertaking. PA: tailor review for a program, repetitive or multiple undertakings, or certain complex projects.
- Are adverse effects already fully known? MOAs are generally tied to resolving identified adverse effects. A project PA may establish phased identification or resolution where effects can't yet be fully determined.
- Can it govern future actions? An MOA governs the undertaking it covers. A program PA may govern future covered undertakings for its duration.
- What should researchers watch? MOAs may show mitigation, design commitments, treatment, monitoring, deadlines, and responsible parties. PAs may show screening rules, exempt or streamlined activities, thresholds, consultation triggers, reporting, phased review, and future implementation.
Execution doesn't mean the same thing as construction
An executed agreement is an important regulatory milestone, but it isn't a notice to proceed, construction contract, funding guarantee, or proof that procurement is imminent.
For an MOA, execution can mean that the agency has reached an agreed path for resolving adverse effects. The federal agency still has to ensure the undertaking is carried out in accordance with the agreement, and other approvals, design work, funding actions, permits, or procurements may remain. For a PA, execution may establish procedures that operate for years. Individual undertakings may still need screening, identification, consultation, treatment plans, or other steps under the PA before physical work occurs.
That is why agreement documents work best as one layer in a larger project timeline. See how to track a preservation project from funding through construction.
What these agreements can reveal as project signals
For firms pursuing preservation work, the value is often in the stipulations and attachments rather than the agreement title. A draft or executed MOA can identify the undertaking, affected historic properties, responsible federal agency, applicant, SHPO/THPO, consulting parties, unresolved design issues, agreed treatment measures, archaeological or architectural documentation, monitoring requirements, deadlines, and the parties responsible for implementation.
A PA can reveal an even longer pipeline. Its appendices may define categories of undertakings, review thresholds, excluded or streamlined activities, treatment standards, reporting requirements, consultation triggers, and procedures for discoveries. Those provisions can help explain why later projects move quickly through review or why a particular class of work repeatedly generates cultural-resource services.
Draft status matters. A proposed agreement shows active consultation, not a settled outcome. Changes between drafts can be meaningful, especially when they alter mitigation, phasing, responsibilities, or treatment requirements. An executed agreement is stronger evidence of a resolved compliance path, but it still shouldn't be mistaken for proof that the project is funded or ready to bid.
Signatures, amendments and implementation can create later signals
Don't stop tracking when the agreement is signed. Implementation can generate treatment plans, survey reports, design submissions, archaeological reports, annual reports, monitoring records, notices of discoveries, dispute correspondence, amendments, and termination notices. Duration deserves its own calendar entry: Section 106 agreements must include a duration provision, but there is no standard three-, five-, or ten-year term. The period should fit the undertaking and the commitments in the agreement.
An approaching expiration date is a meaningful project signal. ACHP guidance warns that an expired agreement can't simply be amended to extend its life. If required stipulations remain incomplete when an MOA or PA expires, the agency's Section 106 responsibility remains unfinished and consultation may need to be reinitiated to develop a new agreement. Tracking the duration clause can therefore reveal likely extension amendments, renewed consultation, or schedule pressure before those actions appear elsewhere.
Those later records can materially change the commercial picture. An amendment may reflect a revised project footprint, schedule, mitigation package, or responsible party. Annual reporting under a PA may expose a series of covered undertakings. A treatment-plan approval can show that a broad agreement is becoming specific enough to generate professional or construction work.
Some information may lawfully be withheld, particularly sensitive information about archaeological sites or historic properties under NHPA Section 304 and 36 CFR 800.11(c). An incomplete public attachment set therefore doesn't necessarily mean the underlying identification work wasn't done.
How to research an MOA or PA
Start with the federal agency because Section 106 responsibility remains with the agency official. Search the agency's project pages, environmental documents, cultural-resource records, notices, and agreement repositories. Then check the relevant SHPO or THPO, ACHP case materials, applicant or owner records, and public meeting or permitting records where applicable.
Read the document itself, including recitals, definitions, appendices and signature pages. Confirm whether it is a draft or executed agreement, identify the undertaking or program it covers, note its effective date and duration, and distinguish signatories, invited signatories, and concurring parties. Then extract implementation deadlines and named deliverables.
If the agreement references properties as 'listed or eligible,' remember that National Register listing isn't itself what triggers Section 106; the federal undertaking and its potential to affect historic properties are what bring Section 106 into play. Finally, look beyond the agreement. Funding decisions, design contracts, environmental approvals, permits, capital plans, and procurement records can tell you whether the regulatory milestone is translating into an active project.
The takeaway
A Section 106 memorandum of agreement and a Section 106 programmatic agreement can look similar on a search-results page, but they can describe very different stages and scales of federal preservation review. An MOA usually documents how adverse effects from a particular undertaking will be resolved. A PA changes or structures the review process for a program, repeated activities, or a qualifying complex project. For project intelligence, both can be valuable because they turn consultation into written commitments, responsible parties, deadlines, treatment requirements, and follow-on records that can be tracked.
The agreement is the signal, not the finish line. Its real value comes from understanding what it governs and what implementation should produce next.