GMP stands for Guaranteed Maximum Price. It's a contract structure where the GC (or CM) commits to delivering the project for no more than a set dollar amount. If costs run over that cap, the contractor eats the difference.
That's the core risk: you've set a ceiling, and everything above it comes out of your fee.
If costs come in under the GMP, what happens to the savings? That depends on the contract. Some owners keep 100% of the savings. Others split it with the GC — often 50/50 — as an incentive to manage costs tightly.
GMP contracts are typically used when design isn't fully complete at the time of contracting. The owner wants to move fast. The GC steps in early, helps develop the scope, and sets a price ceiling based on partially complete documents.
That's exactly why scope gaps are so dangerous in GMP work. You're pricing off incomplete information — and then you're locked into a ceiling.
Both structures fix the price. But they work differently — and they shift risk differently.
| Factor | GMP Contract | Lump Sum Contract |
|---|---|---|
| Design completeness at signing | Partial (60–90% common) | Full (100% construction documents) |
| Who absorbs cost overruns | GC (above GMP) | GC (any overrun) |
| What happens to savings | Split or owner keeps | GC keeps all |
| Transparency required | High — open-book cost reporting | Low — GC profit is private |
| Change order exposure | High (scope incomplete at signing) | Lower (full documents) |
| Typical delivery method | CM at-risk, design-build, negotiated | Design-bid-build, hard bid |
With a lump sum, you price complete documents and keep any savings from a tight buyout. With a GMP, you're open-book — and the owner can see every dollar.
That transparency is the tradeoff for getting on the project early.
You'll find GMP contracts most often in:
In 2026, CM at-risk continues to grow in healthcare, higher education, and public infrastructure. Owners want early GC involvement. That means more GMP exposure for general contractors.
The GMP ceiling isn't the main problem. Scope gaps are.
When design is 70% complete, there are gaps. Systems that aren't fully coordinated. Specs that reference sections not yet written. Site conditions that aren't yet confirmed. You price what you can see — and assume the rest.
If your assumptions are wrong, you're on the hook. The GMP doesn't move just because the architect added three addenda after you set the number.
Scope disputes in construction averaged $340,000 per project in 2026. On a GMP project, those disputes are compounded — because the owner's position is "you knew the scope when you signed."
The practical damage shows up in three places:
Every GMP contract has an inclusions/exclusions list. This is your primary line of defense. But most GCs build these lists manually — reading through 1,500-page project specs and trying to catch what's in and what's out.
That process takes 30–40 hours per bid. And it still misses things.
Provision's Scope Agent reads the full project document set — drawings, specs, addenda — and generates a complete scope-of-work package in under 60 minutes. It pulls inclusions and exclusions directly from the documents, with section citations. Not guesses. Not assumptions.
Across more than 66,000 documents processed, Scope Agent has reviewed over $100 billion in project value. The accuracy on pre-built risk checklists runs at 99.5%. That's the difference between a defensible exclusions list and one that falls apart in a dispute.
Here's what experienced pre-construction teams do to protect themselves in GMP work. None of this is new — but most teams don't execute all of it consistently.
Don't finalize the GMP number until you've done a full scope review. That means reading the specs — all of them. Division 01 general requirements, Division 03 concrete, all the way through. Every assumption you make in lieu of a complete spec is a potential overrun.
A scope of work template helps structure this, but it's only as good as the document review that feeds it.
Your exclusions list needs to be specific enough to defend. "MEP coordination not included" won't hold. "Fire suppression system design by owner's separate contractor per Spec Section 21 00 00 not included" will.
The more precise your language, the less room for interpretation on bid day — and on dispute day.
Fight for control over GMP contingency. Some owners want joint approval on every contingency draw. That's a problem when you need to move fast. The best GMP agreements give the GC discretion up to a threshold — say, $50,000 — without owner approval.
If design changes materially after GMP is set, that should trigger a GMP amendment. Define what "material change" means in the contract. Track design changes against the GMP baseline. Don't let scope creep get absorbed into contingency without documentation.
The contract itself carries risk beyond the GMP ceiling. Indemnification clauses, consequential damages waivers, liquidated damages, and insurance requirements all affect your exposure.
Provision's Risk Review flags contract risk with 99.5% checklist accuracy — 5X more accurate than running specs through a generic AI tool. It's reviewed over 1,000,000 risks across real project documents. That's not a claim about future capability. That's track record.
If you're using ChatGPT to review GMP contract language, you're getting a tool that hallucinates contract terms and doesn't cite spec sections. Risk Review cites the actual clause. That matters when a dispute hits.
Knowing the structure of a GMP isn't enough. The language inside the contract determines how protected you are. These are the clauses that catch GCs off guard most often.
Allowances are dollar amounts for specific items where cost isn't yet determined — tile selection, hardware, landscaping. They're in the GMP but not fully defined. If actual costs exceed the allowance, that difference typically comes back to the owner as a GMP amendment.
Contingency is different. It covers unknown conditions within the existing scope. Know which bucket is which — they're not interchangeable, and misusing them causes owner disputes.
Read it carefully. Some savings clauses only pay out if the full project comes in under GMP — not just your trade packages. A strong buyout doesn't mean anything if a late scope change burns the savings before closeout.
This is the clause that causes the most pain. Many AIA GMP forms include language stating the GC is responsible for work "reasonably inferable" from the contract documents — even if not explicitly shown.
That's a broad standard. It's the language owners use to deny change orders on incomplete design. When you're building your exclusions list, this clause is the reason to be exhaustive.
The document volume on a GMP project — partial drawings, draft specs, owner-issued addenda, supplementary conditions — has always made thorough review nearly impossible in the time available.
That's changing. Not because AI eliminates the problem, but because purpose-built construction AI can process 2,000-page document sets in minutes and surface what matters.
Provision's Chat Agent answers questions directly from your project documents — drawings, specs, contracts, RFIs, addenda — with cited answers in under 20 seconds. Ask "What does the spec say about owner-furnished equipment?" and you get a cited answer. Not a hallucination. Not a summary. The actual clause.
Across 50,000 queries answered on real project documents, the verified accuracy runs at 95%. That's the bar for tools that GCs at firms doing $150M–$600M in revenue can actually rely on.
If you're working on GMP pursuits and want to see how Provision handles your document set, request a demo and bring your own project documents.
Most GMP contracts require open-book cost reporting — the owner can audit invoices, subcontractor agreements, and payroll. That's a feature of the delivery method, not a negotiable item in most cases. Some private owners are less stringent, but healthcare and public owners typically require full transparency.
Owners get price certainty without waiting for 100% complete drawings. GCs get early project involvement and a fee for preconstruction work. The tradeoff works if the GC builds a strong scope and exclusions list upfront.
The contract's savings clause controls this. Common structures: 100% to owner, 50/50 split, or tiered splits based on how far under GMP you came in. GCs doing strong buyout and tight cost management can earn real savings incentives.
A GMP (Guaranteed Maximum Price) contract sets a ceiling on the total project cost. The GC must deliver the project within that cap. Any cost overrun above the GMP comes out of the contractor's fee. If the project comes in under the GMP, the savings may be shared between the owner and GC depending on the contract terms.
A lump sum is priced from complete construction documents. The GC keeps all savings from a tight buyout. A GMP is typically set on partial design, requires open-book cost reporting, and shares savings with the owner. Both cap the price, but lump sum gives the GC more profit privacy and less scope ambiguity at signing.
GMP contingency is a dollar reserve within the contract for unforeseen conditions. It's not for scope changes — it's for unknowns within the defined scope. Control of contingency (who can authorize draws and up to what dollar threshold) is a key negotiation point. GCs should push for independent discretion up to a defined threshold.
Scope gaps are the primary risk. When design is incomplete at GMP signing, assumptions fill the gaps. If those assumptions are wrong, the GC absorbs the overrun. "Reasonably inferable" contract language makes this worse by expanding what the GC is implicitly responsible for beyond what's explicitly drawn.
Generic AI tools like ChatGPT are not reliable for contract review — they hallucinate terms and don't cite actual spec sections. Purpose-built tools like Provision's Risk Review flag risks with 99.5% checklist accuracy, citing the exact clause. Across 1,000,000+ risks reviewed, that level of accuracy is what contract review in a GMP context actually requires.
Manual scope review for a GMP project takes 30–40 hours of estimator time per bid. With AI tools like Scope Agent, that same review generates a complete scope-of-work package in under 60 minutes — with citations to the source documents.
Every item not explicitly included in the GMP scope should be listed by spec section and drawing reference. Vague exclusions don't hold up in disputes. Specific exclusions — referencing the contract document section they relate to — give you a defensible position when an owner pushes back on a change order.
Request a demo of Provision AI and see how we can help you identify risks earlier and bid with confidence.
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