CMAR (Construction Manager at Risk) and CMGC (Construction Manager/General Contractor) describe the same project delivery method under two different labels. In both, the owner hires a construction firm early in design to act as a paid consultant, then transitions that same firm into the general contractor role for construction. When comparing CMAR vs CMGC, the naming split tracks the industry: CMAR is standard in vertical building work, while CMGC is the term federal highway regulations and state transportation agencies use for infrastructure projects.1eCFR. 23 CFR Part 635 Subpart E – Construction Manager/General Contractor Contracting The real differences between the two are narrow: how the construction price gets established, and what federal oversight applies to the pricing decision.
Why Two Names for the Same Thing
The split is largely historical and sectoral. Owners of buildings — hospitals, universities, offices, courthouses — adopted the “at risk” language to describe a construction manager who assumes cost risk under a Guaranteed Maximum Price. State departments of transportation and the Federal Highway Administration built out their own version of the method for highways, bridges, and tunnels, and the federal regulations codified it as CM/GC.2Federal Highway Administration. Construction Manager/General Contractor (CM/GC)
If you are working on a public building, you will almost certainly see the CMAR label. If you are working on a federally funded highway or transit project, you will see CMGC. Some state agencies use the terms interchangeably or have their own hybrid label. The label alone does not tell you what pricing mechanism, procurement rules, or contract form apply — those come from the specific solicitation and the governing regulations.
What Is Identical Under Both Labels
The core structure does not change between the two. Both methods split the construction firm’s involvement into two phases. In the first phase, the firm works alongside the owner’s design team as a paid consultant, reviewing drawings for buildability, flagging materials or sequencing problems, providing cost estimates, and helping the owner see how design decisions affect budget and schedule. Federal CMGC regulations define these preconstruction services to include scheduling, work sequencing, cost engineering, constructability review, cost estimating, and risk identification.3eCFR. 23 CFR 635.504 – CM/GC Requirements CMAR building projects follow the same playbook. The construction manager typically joins around 30 percent design, and some owners bring the firm on even earlier.4Arizona Department of Transportation. Construction Manager at Risk Process Guide
In the second phase, the same firm becomes the general contractor: hiring subcontractors, running the site, and delivering the finished project. The transition happens once the owner and the construction manager agree on a construction price.
The contract structure is also the same. The owner holds two separate contracts, one with the designer and one with the construction manager. Design and construction remain separate contractual relationships, unlike design-build where a single entity holds both.5Associated General Contractors of America. CM At-Risk There is no direct contract between the designer and the construction manager, so formal communication runs through the owner.
Selection procedures follow the same logic under either label. Because neither method uses low-bid competition for the initial award, selection turns on qualifications and approach. Owners publish a Request for Qualifications, shortlist firms based on past performance, safety, and personnel, then issue a Request for Proposals with interviews. Federal CMGC rules allow award based on qualifications, experience, best value, or any combination specified in the solicitation, and require that if interviews are used, every shortlisted firm gets one.3eCFR. 23 CFR 635.504 – CM/GC Requirements CMAR building procurements generally mirror this stage-gate process.
Where the Two Actually Diverge: Pricing
The clearest working difference is how the construction price gets set.
A typical CMAR arrangement produces a Guaranteed Maximum Price. The GMP functions as a cost ceiling: the owner will not pay more than that amount for the defined scope, and the construction manager absorbs any overruns within that scope. The GMP is usually formalized through a contract amendment once the design is developed enough to support reliable estimating.6Acquisition.GOV. GSAM 536.7105-2 – Guaranteed Maximum Price7AIA Contract Documents. FAQs – Choosing an Agreement Between Owner and Construction Manager8ConsensusDocs. 500 Series – CM At-Risk If actual costs come in below the GMP, the contract determines what happens to the savings. Some agreements return everything to the owner. Others include a shared-savings clause that gives the construction manager a negotiated percentage — a 70/30 owner-favored split is common, though the numbers vary.
CMGC projects on public infrastructure often reach the construction price through a more deliberate negotiation rather than a single GMP proposal. The contractor and agency work through an open-book cost model during preconstruction, then the contractor submits a formal price proposal once the design nears completion. If the first proposal falls outside an acceptable range, the parties negotiate, sometimes across multiple rounds. In practice, some CMGC contracts do use a GMP; others use a negotiated lump sum or a cost-plus structure. The label alone does not dictate the pricing mechanism.
The Independent Cost Estimate on CMGC Projects
On CMGC projects using federal highway funds, the agency must perform a price analysis comparing the contractor’s proposed price against the agency’s own engineer’s estimate or an independent cost estimate.9eCFR. 23 CFR 635.506 This third-party check substitutes for the competitive pressure of low-bid procurement. If the independent estimate and the contractor’s number diverge too far, the agency has documented leverage to push back. FHWA considers this independent oversight a defining feature of the CMGC process.2Federal Highway Administration. Construction Manager/General Contractor (CM/GC)
CMAR building projects are not always required to obtain an independent cost estimate. Experienced owners often commission one anyway, because without competitive bidding some form of independent price validation is what protects the owner from overpaying. The difference is that on federal CMGC work, the check is mandatory; on private or public CMAR work, it is a matter of owner discretion.
What Happens If Price Negotiations Fail
Under either label, the owner is not locked in if a price cannot be agreed. Federal CMGC regulations let the contracting agency terminate negotiations and initiate a new procurement, including traditional competitive bidding.3eCFR. 23 CFR 635.504 – CM/GC Requirements Some agencies prohibit the original CMGC contractor from bidding on the rebid, on the theory that preconstruction involvement creates an unfair competitive advantage. Most CMAR building contracts contain a similar off-ramp allowing the owner to put the work out to bid if GMP negotiations stall.
Where the Two Diverge: Regulatory Oversight
CMGC on federally funded highway work sits inside a specific regulatory framework — 23 CFR Part 635 Subpart E — that governs how the agency runs the procurement, evaluates proposals, negotiates price, and validates cost.1eCFR. 23 CFR Part 635 Subpart E – Construction Manager/General Contractor Contracting Those rules dictate what preconstruction services can be procured, how selection criteria must be disclosed, when the independent cost estimate is required, and what documentation must support the price agreement.
CMAR projects are not governed by that federal framework. They operate under state procurement statutes for public building work, or under private contract terms for private owners. Contract forms typically come from the AIA or ConsensusDocs families rather than a federal template. The result is more flexibility on procurement mechanics and price documentation, but also less standardization from one project to the next.
What Does Not Change With the Label
Several things a searcher might expect to differ actually do not.
Risk allocation runs the same way under both. The construction manager bears financial responsibility for cost overruns within the agreed scope once a GMP or negotiated price is in place. Design errors remain the owner’s responsibility under the Spearin doctrine, because the owner furnishes the design through a separately contracted design team. That allocation applies whether the project is labeled CMAR or CMGC.
Bonding rules follow the funding source, not the label. Federal construction contracts over $100,000 trigger Miller Act performance and payment bonds at 100 percent of the contract price during the construction phase.10Office of the Law Revision Counsel. 40 USC 3131 State and local thresholds vary. Preconstruction services generally do not trigger bonding under either method.
Contingency management — separate contractor and owner contingency funds, with unused contractor contingency reverting to the owner at close — works the same way in both. CMGC transportation projects often formalize the process through a risk register maintained jointly during preconstruction, but the underlying structure is the same one CMAR building projects use.
Which Label Applies to Your Project
If the work is a building — public or private — and the owner is selecting a construction manager to provide preconstruction services and later become the general contractor under a GMP, the project is almost certainly CMAR. Expect AIA or ConsensusDocs contract forms, a GMP amendment, and price validation at the owner’s discretion.
If the work is a highway, bridge, tunnel, or transit facility using federal transportation funds, the project is CMGC and 23 CFR Part 635 Subpart E governs. Expect a formal price negotiation, a mandatory independent cost estimate, and stricter procurement documentation. State transportation agencies running CMGC on state-only funds often follow the federal template even when they are not required to.
Beyond those two clear cases, the label alone will not tell you what to expect. Read the solicitation and the draft contract: the pricing mechanism, the role of an independent cost estimate, and the off-ramp if negotiations fail are what actually determine how the project will run.