Fixed-Price vs Cost-Plus Defense Contracts

Neither label establishes the company's eventual profit or cash position. The specific fee formula, funding limits, payment clauses, and work requirements determine the exposure.

On This Page

• Compare the price and fee mechanisms
• See how the same overrun changes the economics
• Separate reimbursement, funding, and cash
• Apply the current defense selection rules
• Read the order and line items
• Make the bid decision from the actual terms

Compare the price and fee mechanisms

“Fixed-price” describes a family of arrangements. Firm-fixed-price (FFP) is the version in which actual performance cost does not reset the price. Cost-plus usually means a cost-reimbursement arrangement with a fee; cost-reimbursement also includes arrangements without a fee.

The table compares the principal mechanisms. “Fee” is the contractual compensation above reimbursable cost, not a promise of company net profit.

Arrangement	What determines payment	What changes when costs rise	Contractor's practical focus
Firm-fixed-price, FFP	Agreed price for the required work	Ordinary overruns reduce profit and can produce a loss	Estimate completion cost and control scope
Fixed-price incentive, firm target, FPIF	Target cost, target profit, sharing formula, and ceiling price	Formula reduces profit; costs above the ceiling can create losses	Model the share line and ceiling together
Cost-plus-fixed-fee, CPFF	Allowable cost plus a negotiated fixed fee	Fee does not rise automatically with actual cost	Protect fee through cost discipline and documentation
Cost-plus-incentive-fee, CPIF	Allowable cost plus a formula-based fee with a minimum and maximum	Fee generally falls as cost exceeds target, within the formula's limits	Check the fee floor, ceiling, and sharing formula
Cost-plus-award-fee, CPAF	Allowable cost, any applicable base fee, and an earned award amount	Award depends on performance evaluation under the award-fee arrangement	Understand evaluation criteria and fee at risk

Source basis: FAR descriptions of FFP, FPIF, CPFF, CPIF, and CPAF, checked September 7, 2026. These mechanical distinctions remain in the revised Part 16; its selection rules are discussed below. The practical-focus column is editorial interpretation.

Another fixed-price variant, economic price adjustment, permits specified increases or decreases tied to agreed prices, labor or material costs, or indexes. It addresses the events named in the clause. It does not make every overrun reimbursable. FAR 16.203-1

An FFP price can also change through applicable contract clauses, such as an authorized equitable adjustment. Absorbing an ordinary cost overrun is different from pricing an authorized change in work. Revised Part 16, section 16.201

Cost-plus also does not mean an automatic percentage markup on whatever the contractor spends. The government prohibits cost-plus-a-percentage-of-cost contracting. A negotiated fixed-dollar fee and an incentive formula are different mechanisms. FAR 16.102

See how the same overrun changes the economics

Consider an illustrative scope of work with an expected cost of $10 million. Compare an FFP price of $11 million with a CPFF arrangement containing $10 million estimated cost and a $1 million fixed fee. These are hypothetical inputs, not quoted defense pricing or typical fee rates.

Assume identical work, no scope changes, no incentives, completion sufficient to earn the entire fee, and all costs allowable under CPFF. For the overrun case, assume the contracting officer increases the estimated cost and the government provides sufficient funding. Exclude taxes, financing costs, and other company expenses outside the stated cost.

FFP contract contribution = contract price minus actual performance cost.

CPFF contract contribution = allowable-cost reimbursement plus fixed fee minus actual performance cost.

Actual cost of the same work	FFP government payment	FFP contribution	CPFF government payment	CPFF contribution
$9 million	$11 million	$2 million	$10 million	$1 million
$10 million	$11 million	$1 million	$11 million	$1 million
$12 million	$11 million	Negative $1 million	$13 million	$1 million

The calculations apply the FFP cost-risk rule and CPFF fixed-fee rule to the stated assumptions. Figures are exact at the displayed precision.

In the overrun case, the CPFF fee stays at $1 million while its share of total payment falls from about 9.1% ($1 million ÷ $11 million) to 7.7% ($1 million ÷ $13 million), rounded to one decimal place. Higher reimbursement therefore does not automatically mean higher earnings. Under FFP, that same $2 million cost increase consumes the original $1 million contribution and creates a $1 million loss.

The CPFF result changes if funding is not increased, some costs are disallowed, or the full fee is not earned. Those are central business risks, not rounding details.

Read the CPFF form as well. The completion form ties the full fee to delivering the specified end product under its terms; the term form concerns satisfactory performance of a specified level of effort over a stated period. A fixed fee does not eliminate the performance obligation. FAR 16.306

Separate reimbursement, funding, and cash

Allowable cost is narrower than money spent

Under FAR 31.201-2, allowability depends on reasonableness, allocation to the contract, applicable accounting requirements, contract terms, and cost-principle limits. Unsupported costs may be disallowed.

For example, if the CPFF overrun scenario includes $200,000 that is finally disallowed, reimbursement becomes $11.8 million. Adding the $1 million fee and subtracting $12 million spent leaves $800,000 of contribution. The assumption that every cost qualifies is therefore worth testing before treating fee as protected earnings.

Estimated cost and allotted funds are separate limits

The Limitation of Cost clause requires specified notifications and limits the government's reimbursement obligation. The Limitation of Funds clause addresses incrementally funded work and the amount currently allotted. A total estimate can exceed the money available for the current increment. Read the incorporated clauses and their notice triggers. FAR 52.232-20, FAR 52.232-22

A useful control is a recurring forecast showing cost incurred, projected near-term spending, estimated cost to complete, remaining allotment, and the next required notice date. Assign responsibility for written notice before a funding limit becomes an immediate production problem. A program team's expectation of more money should not be entered into the forecast as an approved increase.

Payment timing can still require working capital

Reimbursable work requires payment requests and supporting cost information. The Allowable Cost and Payment clause also provides for review and final indirect-cost rate settlement. Interim billing is not necessarily the final cost determination. FAR 52.216-7

FFP does not necessarily mean waiting until all work is delivered to receive cash. Contract financing can include performance-based payments where authorized; these are financing payments rather than payment for accepted items. FAR 32.1001

Build a cash schedule separately from the margin estimate. Put supplier deposits, payroll, invoice submission, expected receipts, and any financing liquidation on that schedule. Two contracts with the same expected contribution can require very different amounts of cash to perform.

Apply the current defense selection rules

Defense Class Deviation 2026-O0045, effective March 16, 2026, directs contracting officers to use the revised FAR Part 16 and attached defense supplement and procedures in place of the specified codified text. An older FAR section number alone can therefore be an incomplete guide to a new procurement. Defense deviation memorandum

The current revised Part 16 makes fixed-price types the preferred default. Cost reimbursement remains available when requirements or performance uncertainty prevent sufficiently reliable fixed pricing. It requires suitable cost accounting, approved acquisition planning, and government capacity to manage the work; commercial products and services cannot use it.

Revised section 16.104 also requires agency-head justification for covered defense contracts and orders at or above $100 million, subject to exceptions including research and development and major-system pre-production development. Hybrid and ordering arrangements have specific coverage rules. This is an approval requirement, not a blanket ban on cost-plus work.

The defense deviation separately prohibits cost-reimbursement line items for production of major defense acquisition programs unless its cited exception applies. Its guidance also cautions against an unrealistic FPIF ceiling and against FFP production pricing before costs stabilize. Defense deviation, attachments A1 and A2

For a supplier, the practical distinction is whether uncertainty can be priced. Repeat production with stable specifications and reliable supplier quotations supports a different discussion from development whose test effort cannot yet be estimated. A firm-price offer should state assumptions about quantities, schedule, rework, and customer-provided inputs. A proposed cost-reimbursement approach should explain the specific uncertainty and how costs will be controlled.

Read the order and line items

An indefinite-delivery, indefinite-quantity (IDIQ) contract is an ordering structure. It does not, by itself, tell you whether an order uses fixed-price or cost-reimbursement pricing. Indefinite-delivery contracts can support appropriate pricing arrangements. FAR 16.501-2

For a mixed award, list each contract line item, its work, pricing type, funded amount, fee mechanism, and payment clause. Keep a development line's exposure separate from a production line's exposure. A headline award value is a poor substitute for that breakdown.

Perform the same reading exercise on subcontracts. Do not assume that the prime contractor's reimbursement arrangement establishes your own payment rights. Compare the terms actually offered to you with the costs and delivery commitments you must accept.

Make the bid decision from the actual terms

Before committing a price or accepting an award, resolve five questions:

1. Can the work be bounded? Reconcile specifications, deliverables, acceptance conditions, quantities, and schedule with the estimate.
2. What can move the price or fee? Identify the actual adjustment clauses, incentive formula, ceiling, and award-fee conditions.
3. What happens in the downside case? Recalculate completion cost using plausible supplier delays, rework, and labor assumptions. Label estimates and uncertainties.
4. Which costs and payments need evidence? Confirm accounting capability, supporting records, indirect-rate assumptions, billing terms, and funding notices.
5. Can the company finance performance? Check cash needs against the payment schedule, separately from expected earnings.

Choose the commercial position your company can perform under the solicitation's permitted terms. FFP offers the opportunity to retain cost savings while exposing the contractor to overruns. Cost-plus reduces that particular exposure but leaves cost allowability, funding, fee, and cash timing to manage. The sound bid decision comes from testing all of those terms against the same scope of work.

Source notes

• FAR 16.202-1: Firm-fixed-price cost-risk mechanism.
• FAR 16.301-1: Reimbursement of allowable costs within contractual limits.
• FAR 16.403-1: Fixed-price incentive targets, profit adjustments, and ceiling.
• FAR 16.306: Fixed fee and CPFF completion and term forms.
• FAR 16.405-1: Cost-plus-incentive-fee mechanism.
• FAR 16.405-2: Cost-plus-award-fee components.
• FAR 16.203-1: Economic price adjustment categories.
• FAR 16.102: Prohibition on cost-plus-a-percentage-of-cost contracting.
• FAR 31.201-2: Cost allowability and supporting records.
• FAR 52.232-20: Limitation of Cost clause.
• FAR 52.232-22: Limitation of Funds clause.
• FAR 52.216-7: Allowable Cost and Payment clause.
• FAR 32.1001: Performance-based contract financing.
• Defense Class Deviation 2026-O0045: Defense implementation and supplementary contract-type restrictions and guidance.
• Revised FAR Part 16: Current deviation text, including selection and justification requirements.
• FAR 16.501-2: Pricing arrangements within indefinite-delivery contracts.

Apply the solicitation's incorporated clauses, amendments, and applicable agency deviations to a specific procurement.

Last checked: September 7, 2026.