Types of Government Contracts: Fixed-Price, Cost-Reimbursement, and More

Federal acquisition law establishes a structured taxonomy of contract types, each allocating financial risk between the government and contractor in distinct ways. The Federal Acquisition Regulation (FAR), codified at 48 C.F.R. Parts 16 and beyond, governs which contract type an agency may select and under what conditions. Understanding these distinctions is essential for any contractor bidding on federal work, since the wrong contract type can expose a firm to unrecoverable cost overruns or disqualify a proposal entirely. This page covers the full spectrum of contract types, their mechanical structures, the regulatory drivers behind type selection, and the tradeoffs that make certain arrangements contentious.

• Definition and scope
• Core mechanics or structure
• Causal relationships or drivers
• Classification boundaries
• Tradeoffs and tensions
• Common misconceptions
• Checklist or steps (non-advisory)
• Reference table or matrix

Definition and scope

A government contract type is a defined legal arrangement specifying how costs are measured, how payment is calculated, and which party bears residual financial risk when actual performance costs diverge from estimates. The Federal Acquisition Regulation at FAR Part 16 organizes contract types into two primary families — fixed-price and cost-reimbursement — plus a hybrid category of incentive contracts and several special-purpose arrangements including time-and-materials, labor-hour, and letter contracts.

The FAR defines contract type selection as a primary responsibility of the contracting officer, who must document the rationale for any cost-reimbursement arrangement in the acquisition plan (FAR 16.103(d)). The scope of this classification system extends to all executive branch agencies subject to the FAR, including the Department of Defense, General Services Administration, and civilian agencies. Defense-specific contract types and supplemental rules appear in the Defense Federal Acquisition Regulation Supplement (DFARS).

Core mechanics or structure

Fixed-Price Contracts

Under a firm-fixed-price (FFP) contract, the contractor agrees to deliver a defined scope of work for a single agreed price, regardless of actual costs incurred. FAR 16.202 designates FFP as the preferred contract type when requirements are well-defined and risk is estimable. The price does not adjust unless the parties formally modify the contract scope.

A fixed-price with economic price adjustment (FP-EPA) contract introduces a pre-defined formula allowing price revision tied to external indices — commodity price escalators or labor indices published by the Bureau of Labor Statistics, for example — protecting both parties from macro-level inflation on long-duration efforts (FAR 16.203).

Cost-Reimbursement Contracts

Cost-reimbursement (CR) contracts reimburse the contractor for all allowable, allocable, and reasonable costs as defined by FAR Part 31 and the Cost Accounting Standards (CAS). The government bears the residual cost risk. Subtypes include:

• Cost-Plus-Fixed-Fee (CPFF): The contractor receives reimbursed costs plus a negotiated fixed fee that does not vary with performance. FAR 16.306 caps the fixed fee at 10 percent of estimated cost for research contracts and 15 percent for most other efforts.
• Cost-Plus-Incentive-Fee (CPIF): The fee adjusts based on a formula comparing target cost to actual cost, creating a cost-sharing arrangement within a defined range. FAR 16.405-1 governs CPIF mechanics.
• Cost-Plus-Award-Fee (CPAF): A subjective performance evaluation by a fee-determining official drives a variable award fee pool, often structured as a base fee plus an earned pool. FAR 16.405-2 establishes procedural requirements for award-fee boards.

Time-and-Materials and Labor-Hour Contracts

Time-and-materials (T&M) contracts pay fixed hourly labor rates plus material costs at cost (FAR 16.601). The government assumes cost risk on hours consumed, making T&M appropriate only when it is impossible to estimate the extent of work at contract award. Labor-hour contracts are identical to T&M except no materials are furnished. FAR requires a ceiling price on T&M and labor-hour contracts, and contracting officers must conduct surveillance to ensure contractors are not incentivized to prolong performance.

Causal relationships or drivers

The selection of a contract type is causally determined by two variables: the degree of requirement definition and the allocation of technical and cost risk. FAR 16.103(a) states explicitly that contract type selection depends on the degree of cost risk involved in the specific acquisition and the extent of responsibility the contractor assumes.

When program requirements are mature, designs are complete, and historical cost data are available, the risk calculus favors fixed-price. When work involves research, development of novel systems, or performance in highly uncertain environments — such as early-phase research and development contracts — cost-reimbursement is appropriate because a contractor cannot reasonably price unknown technical risk.

Regulatory reform has also shaped type selection. The Weapon Systems Acquisition Reform Act of 2009 increased scrutiny of cost-reimbursement usage in major defense acquisition programs, directing the Department of Defense to reduce reliance on cost-type contracts as programs mature. The Defense Contract Audit Agency (DCAA) plays a central auditing role in cost-reimbursement environments, reviewing incurred cost submissions and forward pricing rate proposals to ensure cost reasonableness.

Classification boundaries

The FAR classification system draws firm boundaries based on risk allocation:

• Fixed-price family: FFP, FP-EPA, fixed-price incentive (firm target and successive targets), fixed-price with prospective/retroactive price redetermination.
• Cost-reimbursement family: Cost (no fee), cost-sharing, CPFF, CPIF, CPAF.
• Hybrid and indefinite-delivery types: T&M, labor-hour, indefinite-delivery/indefinite-quantity (IDIQ), definite-quantity and requirements contracts.
• Special-purpose: Letter contracts (undefinitized contract actions), basic ordering agreements, and blanket purchase agreements (BPAs).

Letter contracts are a distinct edge case. FAR 16.603 permits their use only when the agency cannot await definitization of a formal contract, and FAR 16.603-2(c) limits the amount authorized for obligation before definitization to 50 percent of the estimated contract price. Definitization must occur within 180 days of contract award or before 40 percent of work is completed — whichever is earlier.

The government-wide acquisition contract (GWAC) and GSA Schedules mechanisms are ordering vehicles, not stand-alone contract types; each task order placed against these vehicles carries its own designated contract type (typically FFP or T&M).

Tradeoffs and tensions

Fixed-price contracts shift all cost risk to the contractor. When requirements are poorly defined at award, this creates structural tension: the contractor may underbid to win, then seek contract modifications to recover margin. This dynamic — sometimes called "buying in" — generates modification disputes and inflates total program costs. The Government Accountability Office (GAO) has documented this pattern repeatedly in defense acquisition reviews.

Cost-reimbursement contracts shift risk to the government but can reduce contractor incentive to control costs. CPFF, in particular, provides no marginal financial incentive for the contractor to finish below target cost, since the fee is fixed regardless of cost outcome. CPIF and CPAF structures were designed to address this, but CPAF has drawn criticism for subjective fee determinations that may not reliably reflect objective performance.

T&M contracts present the most acute moral hazard: because the contractor is paid per hour at a fixed rate, there is a direct financial incentive to expand hours worked. FAR 16.601(c) restricts T&M use specifically because it provides "no positive profit incentive to the contractor for cost control or labor efficiency." Contracting officer surveillance requirements under T&M arrangements are therefore more intensive than under FFP.

For contractors pursuing small business set-asides, the contract type affects financial planning materially. A small business with limited working capital may struggle to absorb cost-risk on a large FFP development contract, while a CPFF arrangement stabilizes cash flow but requires compliance with CAS and DCAA audit readiness.

Common misconceptions

Misconception: Cost-reimbursement means unlimited reimbursement. Cost-reimbursement contracts include a funded ceiling — the estimated cost plus fee — and the contractor is not authorized to exceed that ceiling without a contract modification. FAR 52.232-20 (Limitation of Cost) and FAR 52.232-22 (Limitation of Funds) clauses are standard inclusions that require the contractor to notify the contracting officer when 75 percent of the estimated cost or funds have been expended.

Misconception: T&M contracts guarantee payment for all hours worked. T&M contracts carry a not-to-exceed ceiling price (FAR 16.601(d)), beyond which the contractor works at its own risk. The government is not obligated to fund work above the ceiling.

Misconception: FFP contracts eliminate audit exposure. DCAA audit authority extends to FFP contracts in specific circumstances, including defective pricing reviews under the Truth in Negotiations Act (now codified as the Truthful Cost or Pricing Data statute at 10 U.S.C. § 3702 for DoD). If a contractor certified cost or pricing data during negotiations, DCAA may audit for defective pricing regardless of contract type.

Misconception: IDIQ contracts are a contract type. IDIQ is a delivery ordering mechanism, not a pricing arrangement. The contract type for each IDIQ task order is independently designated. A single IDIQ vehicle may support both FFP and T&M task orders depending on the nature of individual orders. Comprehensive orientation on contractor responsibilities across all contract structures is available through the Government Contractor Authority resource index.

Checklist or steps (non-advisory)

The following elements appear in FAR-prescribed acquisition planning and documentation when a contract type is being established or justified:

1. Requirement definition assessment — Document the completeness of performance work statement or statement of work, including whether design specifications are at 100 percent completion.
2. Risk assessment — Identify technical risk areas, cost estimation uncertainty ranges, and schedule risk factors consistent with FAR 16.103(a).
3. Historical cost data review — Retrieve comparable program cost actuals from DCAA, forward pricing rate agreements, or prior contract files.
4. Contract type determination — Select from FAR Part 16 taxonomy; document rationale in writing, especially for any cost-reimbursement selection.
5. Profit/fee structure determination — Establish target fee, minimum/maximum fee ranges, or award-fee pool as applicable; apply fee limitations from FAR 15.404-4 and agency supplements.
6. Limitation-of-cost/limitation-of-funds clause insertion — Include FAR 52.232-20 or 52.232-22 as applicable for CR contracts.
7. Surveillance plan establishment — For T&M and labor-hour contracts, document the contracting officer's representative surveillance methodology under FAR 16.601(c).
8. Undefinitized contract action (UCA) tracking — If a letter contract is issued, establish definitization milestones consistent with FAR 16.603-2 timing requirements.
9. Audit readiness confirmation — Verify contractor accounting system adequacy for any cost-reimbursement award; DCAA Form 1 findings should be resolved prior to award.
10. Modification controls — Establish a change management protocol referencing FAR 43 to prevent scope creep from converting effective contract type risk allocation post-award.

Reference table or matrix