Federal Contract Types Explained: FFP, T&M, and Cost-Reimbursement

The Decision That Shapes Every Line of Your Proposal

When a contracting officer (CO) selects a contract type, that choice determines who carries the performance risk, how your invoices are structured, and what accounting systems you need to survive an audit. An offeror who misreads the contract type in Section B of an RFP can price itself into a loss, propose the wrong cost elements, or submit a volume that the government will reject outright. Before your capture team builds a price-to-win model or drafts a cost narrative, you need a working command of the three dominant contract families: Firm-Fixed-Price (FFP), Time-and-Materials (T&M), and Cost-Reimbursement.

Firm-Fixed-Price (FFP): You Own the Risk

FFP is the government's preferred contract type under FAR 16.202-1. The price is set at award and does not change regardless of your actual costs. If you estimated 1,200 labor hours and the work takes 1,800, the government pays the original price and you absorb the overrun. If you finish in 900 hours, you keep the savings.

The CO is required to use FFP when the requirement is well-defined and the risk of performance is manageable. Think commercial products on a GSA MAS order, recurring janitorial services, or a software license renewal. The RFP will typically reference FAR 52.212-4 for commercial items or FAR 52.232-1 (Payments) for fixed-price contracts.

What this means for your proposal

• Your basis of estimate (BOE) is everything. A weak BOE produces a price that either leaves margin on the table or guarantees a loss. Auditors and source selection evaluators both scrutinize BOEs on FFP contracts, especially for services.
• Scope definition is your protection. If the Statement of Work (SOW) is vague, an FFP vehicle can expose you to unlimited scope creep. Identify ambiguities during the question-and-answer (Q&A) period and get clarifications on the record before the closing date in the solicitation.
• Past performance on similar scope matters more. Evaluators want evidence that you have delivered comparable work at a predictable cost. CPARS ratings that reference on-budget delivery are directly relevant here.

Time-and-Materials (T&M): Shared Risk, Tighter Oversight

A T&M contract pays you a fixed hourly rate for each labor category plus the actual cost of materials, with no profit or fee on materials (FAR 16.601). The hourly rate is fixed, meaning your labor overhead and profit are baked in, but the total contract value floats with the hours actually worked. The government caps total expenditure with a ceiling price; you cannot exceed it without a modification.

COs use T&M when the level of effort cannot be estimated with enough confidence to support FFP. Common examples include IT help desk support with unpredictable ticket volume, engineering studies where the scope may expand based on findings, or surge maintenance contracts. Because T&M shifts cost risk toward the government, FAR 16.601(b) requires a determination and findings (D&F) that no other contract type is suitable.

What this means for your proposal

• Your labor category descriptions must be precise. The fixed hourly rates you propose are tied to specific labor categories. If the government later disputes whether a task falls under a senior engineer rate or a journeyman rate, you need clear category definitions to defend your invoices.
• Certified cost or pricing data may apply. On T&M contracts above the threshold in FAR 15.403-4 (currently $750,000 for most procurements), you may need to certify the accuracy of your proposed rates. Defective pricing findings can trigger price reductions after award.
• Surveillance is intensive. Contracting Officer's Representatives (CORs) on T&M contracts are required to monitor labor hours closely. Your project management approach and timesheet controls belong in your management volume.

Cost-Reimbursement: The Government Absorbs Cost Risk

Under a cost-reimbursement contract, the government pays your allowable, allocable, and reasonable costs plus a fee structure that varies by subtype. The main subtypes are Cost-Plus-Fixed-Fee (CPFF), Cost-Plus-Incentive-Fee (CPIF), and Cost-Plus-Award-Fee (CPAF). FAR Subpart 16.3 governs all of them.

Cost-reimbursement vehicles appear most often in research and development (R&D), complex systems integration, and classified programs where the government cannot define requirements precisely enough to accept a fixed price. The offeror estimates costs, the government funds to that estimate, and both parties share the risk that actual costs may exceed the estimate.

What this means for your proposal

• Accounting system adequacy is a gate, not a checkbox. Before award of a cost-reimbursement contract, the Defense Contract Audit Agency (DCAA) or another cognizant federal agency will review your accounting system. An inadequate system finding can disqualify you. If your firm has never held a cost-type contract, address system readiness explicitly in your proposal and consider a pre-award audit request.
• Indirect rate structures are scrutinized. Your fringe, overhead, and G&A rates must be defensible. Evaluators compare your proposed rates against DCAA-audited actuals or forward-pricing rate agreements (FPRAs). Unexplained rate spikes are a red flag in source selection.
• Fee type signals incentive alignment. CPFF pays a fixed fee regardless of performance, so it offers the least incentive for cost control. CPIF ties fee to cost and schedule targets. CPAF introduces a subjective performance evaluation. When the RFP gives you latitude to propose a fee structure, choose one that reflects your confidence in your cost estimate and your past performance narrative.

Hybrid and Indefinite-Delivery Vehicles Add Complexity

Many large programs use hybrid contract line item numbers (CLINs) that mix types within a single contract. A task order under a Governmentwide Acquisition Contract (GWAC) might carry FFP CLINs for deliverables and a T&M CLIN for surge labor. An IDIQ vehicle sets a ceiling but does not specify type at the ordering level; each task order can carry its own type.

When you are responding to a task order RFP under an IDIQ, read the ordering-level instructions carefully. The base IDIQ contract type does not automatically govern your task order pricing. Some agencies issue task orders as FFP even when the underlying IDIQ is a cost-type vehicle, and vice versa.

Matching Contract Type to Your Capabilities

Contract type selection is not just the government's decision. In negotiated acquisitions, an offeror can propose an alternative contract type in its technical or price volume if the RFP permits, and some solicitations explicitly invite discussion of contract type during exchanges. A capture team that understands the risk profile of each type can make a credible case for a structure that protects margin without appearing to shift unreasonable risk to the government.

When you review an RFP, map the contract type against three questions: Can you bound the scope well enough to price FFP profitably? Do you have the accounting infrastructure to support cost-reimbursement? Does the T&M ceiling give you enough room to staff the work without eating your fixed rate margin? The answers shape not just your price but your entire proposal strategy.

Organizing the requirements, cost elements, and past performance evidence for any of these contract types is easier when your team has a structured way to track what the solicitation demands against what your proposal draft actually addresses. Reach out for a brief consult to talk through how to structure your capture and proposal workflow for the contract type in front of you.

Takeaway

FFP puts cost risk on the contractor and rewards accurate estimating. T&M shares risk but demands tight labor category discipline and COR oversight. Cost-reimbursement shifts risk to the government but requires auditable accounting systems and defensible indirect rates. Know which type you are bidding before you write a single page of your proposal, because the contract type determines the evidence, the pricing structure, and the compliance obligations that follow you through performance.

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