Federal Contract Types — FFP, CPFF, T&M, IDIQ, and GWACs

The federal government has two levers when structuring a contract: how it prices the work (fixed vs. cost-reimbursable) and how it defines the quantity (definite vs. indefinite). The FAR (Part 16) codifies the resulting spectrum across a single dimension that most people miss — risk allocation. A firm-fixed-price (FFP) contract puts all cost overrun risk on the contractor; a cost-plus-fixed-fee (CPFF) contract transfers all of it to the taxpayer. Every contract type between those poles is a negotiated risk-sharing arrangement, and choosing the wrong type for a given procurement is one of the most consistent drivers of cost growth in federal contracting. The DOGE scrutiny of open-ended T&M and cost-plus contracts is the most recent manifestation of a decades-old tension between flexibility (which agencies want) and cost control (which Congress and OMB want).

Legal Authority

• 41 U.S.C. § 3301 — Competition in Contracting Act: requires federal agencies to use competitive procedures and select contract types that maximize competition and best serve the government's interests; foundation for FAR Part 16's preference for firm-fixed-price contracts
• 10 U.S.C. § 3321 and 41 U.S.C. § 3905 — Prohibition on cost-plus-percentage-of-cost contracts: Congress explicitly bans this contract type because it creates perverse incentives to increase spending in order to increase fees
• 48 CFR Part 16 (FAR Part 16) — Federal Acquisition Regulation: defines all authorized contract types (fixed-price, cost-reimbursement, time-and-materials, labor-hour, IDIQ), specifies conditions for using each type, and requires contracting officers to use firm-fixed-price whenever requirements are sufficiently definite

Key Mechanics

Federal contract types are organized around one core variable: who bears the risk of cost overruns. Firm-fixed-price (FFP) contracts — the FAR's preferred type — place all cost risk on the contractor; if a contractor bids $10 million and the work costs $12 million, the contractor absorbs the loss. Cost-reimbursement contracts (CPFF, CPAF, CPIF) shift that risk to the government: the agency pays whatever allowable costs are incurred, plus a fixed or incentive-based fee. Time-and-materials (T&M) contracts are the most government-exposed: the agency pays the contractor's labor hours at fixed billing rates plus actual materials costs, with no ceiling on how many hours may be needed. Between these poles sit incentive-type contracts (FPIF, CPIF) that share cost risk in specified ratios. Indefinite-delivery, indefinite-quantity (IDIQ) contracts are a delivery vehicle, not a pricing type — they allow agencies to order variable quantities at pre-negotiated prices without committing upfront to a definite quantity, forming the backbone of large multi-award vehicles like GWACs.

The Risk Spectrum (FAR Part 16)

Cost-Plus-Percentage-of-Cost (CPPC) is prohibited by 10 U.S.C. § 3321 and 41 U.S.C. § 3905 — it creates the perverse incentive to spend more to earn more.

Fixed-Price Contracts

Firm-Fixed-Price (FFP) — FAR 16.202

FFP is the preferred contract type — FAR 16.104 requires contracting officers to use it whenever requirements are sufficiently definite. The contractor agrees to deliver at a specific price regardless of actual costs. All cost overrun risk falls on the contractor; any savings are profit. FFP contracts account for the majority of federal contract obligations by dollar value and are required for any acquisition that can support them.

FFP is not appropriate when requirements are undefined, when the government lacks independent cost data, or when commercial pricing data isn't available for comparison. Forcing FFP on ill-defined requirements shifts risk to contractors who then build in contingency — producing higher prices and disputes over scope.

Fixed-Price Incentive Firm (FPIF) — FAR 16.403-1

FPIF contracts use a share ratio and point of total assumption (PTA) to split cost risk. Below the target cost, contractor and government share savings; above target, they share overruns up to a ceiling — at the PTA, the contractor absorbs all further overruns. FY2024 DoD major system contracts frequently use FPIF for production phases after cost data has been established.

Cost-Reimbursement Contracts

Cost-Plus-Fixed-Fee (CPFF) — FAR 16.306

CPFF pays allowable costs plus a fixed fee set at contract award — the fee does not change with costs. It is appropriate when requirements are not defined enough for FFP and the contractor cannot bear cost risk (e.g., basic research). It is heavily used at DOE national laboratories, NASA R&D programs, and early-phase weapon system development. The fixed fee is typically 7–10% of estimated cost. Critically, because cost growth does not increase the fee, it does not reward cost efficiency either.

Cost-Plus-Award-Fee (CPAF) — FAR 16.305

CPAF pays allowable costs plus a variable award fee determined by an evaluation board's subjective assessment of contractor performance. The award fee pool is typically 5–15% of estimated cost, allocated in periodic evaluations (quarterly or annual). GAO studies consistently find that agencies award >90% of the available fee even on problem programs — reducing its incentive effect. Still heavily used for logistics, operations support, and large service contracts where performance is hard to quantify in advance.

Cost-Plus-Incentive-Fee (CPIF) — FAR 16.304

CPIF uses a formula to adjust fee based on actual vs. target cost outcomes, within a fee minimum and maximum. More objective than CPAF — fee adjustments are mathematical, not evaluative. Appropriate when cost and performance targets are defined enough to set incentive points but not precise enough for fixed-price.

Time-and-Materials and Labor-Hour

Time-and-Materials (T&M) — FAR 16.601

T&M pays for labor at fixed hourly rates (which include profit) and materials at cost. The government bears unlimited cost risk above the ceiling price (which must be set). T&M is appropriate only when it is not possible at the time of placing the contract to estimate accurately the extent or duration of the work — a high bar that agencies frequently circumvent. DOGE's 2025 review identified T&M as the contract type most prone to cost overruns and scope creep, and the Trump administration issued guidance directing agencies to convert T&M vehicles to FFP where feasible.

Ceiling price: FAR 16.601(d) requires T&M contracts to include a ceiling price the contractor may not exceed without written authorization — a critical protection that is sometimes poorly enforced.

Indefinite-Delivery Vehicles

Indefinite-delivery contracts separate the basic contract (establishing terms) from task or delivery orders (specifying actual work). They are among the most common structures in federal contracting, especially for IT, professional services, and logistics.

IDIQ — Indefinite Delivery, Indefinite Quantity (FAR 16.504)

IDIQ contracts require a minimum guaranteed order (which can be as low as $1) and a ceiling quantity, with actual orders placed by task/delivery orders during the contract period. They may be single-award (one contractor) or multiple-award (several contractors who compete for task orders). Multiple-award IDIQs are now the default for large service acquisitions — they preserve competition at the task order level while reducing the administrative burden of full competition for each order.

GWACs (Governmentwide Acquisition Contracts): IDIQs that multiple agencies can use, designated by OMB. Major GWACs include:

• Alliant 2 (GSA) — IT services, ceiling $50B
• CIO-SP3 (NIH) — IT health services
• OASIS+ (GSA) — professional services, management consulting
• SeaPort-NxG (Navy) — engineering and technical services

MACs (Multi-Agency Contracts): Similar to GWACs but without formal OMB designation; agencies sometimes run them for their own use and grant access to others.

Definite-Quantity and Requirements Contracts (FAR 16.502, 16.503)

Definite-quantity contracts specify exact quantities; requirements contracts promise to order all of the government's needs in a category from the contract holder — a powerful vehicle that has faced antitrust scrutiny for foreclosing competition.

Blanket Purchase Agreements (BPAs) — FAR 13.303

BPAs are simplified acquisition tools — essentially a charge account established with a vendor. Agencies can place individual orders without a separate competition each time, drawing against the BPA ceiling. Heavily used for recurring supply needs below the simplified acquisition threshold ($250,000). GSA Schedule BPAs are established against Schedule contracts — a common vehicle for small-to-medium agency IT and professional service needs.

Delivery/Task Order Competitions

For multiple-award IDIQs, FAR 16.505 governs fair opportunity — all awardees must receive a fair opportunity to be considered for each order above $3,500 (with limited exceptions). This is a major litigation area: order-level protests (to the agency, not GAO or COFC) are the most common dispute mechanism for IDIQ order awards.

Implementing Regulations

The Federal Acquisition Regulation's 48 CFR Part 17 — Special Contracting Methods — governs contracting vehicles and techniques that fall outside the standard FFP/cost-reimbursement/IDIQ framework. Part 17 is authority-driven: each subpart implements a specific statute or executive authority that expands what contracting officers can do. Key subparts:

• Subpart 17.1 — Multiyear Contracting (§§ 17.101–17.110): multiyear contracts allow the government to buy known requirements across up to 5 years in a single award rather than re-competing annually; the core benefit is that contractors can invest in production efficiencies (dedicated tooling, workforce training, long-lead material procurement) knowing they have multi-year demand, enabling lower unit prices. The mechanism: a multiyear contract includes cancellation ceilings — if Congress fails to appropriate funds in a future year and the government cancels, the government must pay the contractor the unamortized portion of startup costs already incurred (§ 17.104 — the cancellation ceiling is listed in the solicitation so bidders price it in). Contracting officers must document that multiyear contracting offers substantial benefits not available through annual contracts and that the requirement is stable. For DoD, NASA, and Coast Guard, specific statutory authority (10 U.S.C. § 3501 et seq.) governs; other civilian agencies use 41 U.S.C. § 3903. Heavily used in defense weapon system production, where annual re-competition would eliminate long-lead production economies.

• Subpart 17.2 — Options (§§ 17.200–17.208): options are unilateral government rights to extend a contract's scope, duration, or both without further competition; the option price must be evaluated at award (§ 17.206 — contracting officer must include option prices in the award evaluation, not just base period) to prevent lowballing the base with inflated option prices. Options must be exercised within the timeframes specified; an unexercised option lapses and cannot be revived without a new competition. Option periods are the standard vehicle for recurring service contracts (1 base year + 4 option years = 5-year performance period) — nearly every federal service contract uses this structure. Options must be in the government's interest to exercise (§ 17.207 — contracting officer certifies the option price is still fair and reasonable and funds are available before exercising).

• Subpart 17.5 — Interagency Acquisitions (§§ 17.500–17.504): interagency acquisition is when one agency (the requesting agency) places an order against another agency's (the servicing agency's) contract. The GSA Schedules program, GWACs, and other government-wide vehicles are built for this. The requesting agency must determine that using an interagency vehicle is in the government's interest and that the vehicle's scope covers the requirement (§ 17.502-1 — Economy Act orders require a determination that the use of another agency's contract is more economical or otherwise more appropriate than a new direct procurement). Business line: OMB and GAO have flagged interagency acquisition abuse — agencies sometimes use another agency's vehicle to avoid their own competition requirements; the requesting agency's contracting officer remains responsible for ensuring the acquisition complies with the requesting agency's legal authorities even when ordering off another agency's vehicle.

• Subpart 17.6 — Management and Operating Contracts (§§ 17.600–17.605): M&O contracts are the vehicle DOE uses to manage its national laboratories (Los Alamos, Lawrence Livermore, Oak Ridge, Argonne, etc.) and nuclear weapons complex facilities. Under an M&O contract, the contractor manages a government-owned facility using government-provided resources — essentially operating as a steward of federal property and workforce rather than performing discrete deliverables. M&O contracts are the largest contract value category in the civilian federal government; DOE's M&O portfolio exceeds $20 billion annually. Profit under M&O contracts is typically expressed as fee on allowable costs, with award fee tied to DOE's evaluation of contractor performance against program objectives. Because the contractor is managing inherently governmental infrastructure, M&O contracts are subject to intensive government oversight and unique procurement requirements not applicable to standard commercial contracts.

• Subpart 17.8 — Reverse Auctions (§§ 17.800–17.803): a reverse auction is a real-time competitive bidding event where multiple sellers compete to offer the lowest price for a well-defined requirement; unlike standard sealed-bid procurement, reverse auctions allow iterative bidding — sellers can see they've been undercut and lower their price in real time until the auction closes. Reverse auctions are most effective for commodity supplies and simple services with clearly defined specifications (office supplies, fuel, janitorial services, standardized IT hardware). FAR Subpart 17.8 (added in recent years) establishes basic requirements: the contracting officer must determine that a reverse auction is appropriate for the requirement, must document the rationale, and must ensure that price alone is the evaluation criterion or that technical factors have been pre-screened before the auction begins. Reverse auctions may not be used when technical factors are significant drivers of value — using them for complex services risks awarding to the lowest price rather than the best value.

Recent rulemakings: Subpart 17.8 (reverse auctions) was added by an interim rule in 2024 implementing the Requirements Regarding Reverse Auctions (a 2021 statutory requirement); the final rule codified reverse auction procedures across civilian and defense contracting.

48 CFR Part 37 — Service Contracting: the FAR's framework for acquiring services — the dominant form of federal contracting by contract count, covering everything from janitorial services to professional consulting to health care. Services represent roughly 60% of total federal contract spending annually. Part 37 establishes requirements and preferences that cut across all service contract types:

• § 37.102 — Performance-based acquisition (PBA) as the preferred method: PBA is the government's stated preference for all service contracts (codified by the Services Acquisition Reform Act of 2003); under PBA, the contract defines what the contractor must achieve (measurable outcomes, performance standards) rather than how to achieve it; the government evaluates contractor performance against those standards; this shifts risk to the contractor and creates incentives for efficiency; the statement of objectives (SOO) or performance work statement (PWS) is the PBA instrument — contrasting with a detailed statement of work (SOW) that specifies the exact tasks to be performed; the "prefer PBA" instruction is real but not absolute — PBA works best when outcomes are measurable and definable; for advisory services and specialized technical work, outcomes are often too qualitative to support rigorous PBA

• § 37.104 — Personal services contracts: personal services contracts are generally prohibited for federal agencies; a personal services contract is one that creates an employer-employee relationship — where a government employee supervises the contractor's personnel on a continuing daily basis, sets their working hours, dictates their methods, and treats them as members of the government workforce; this prohibition exists because Congress has not authorized agencies to bypass the civil service system by using contractors as de facto employees; the practical test: if government supervisors routinely tell individual contractor workers what to do, when to do it, and how to do it (rather than managing to contract deliverables), the contract may be improperly personal; violations expose agencies to OIG criticism and potentially force a determination whether the contractors should have been federal employees subject to personnel ceilings and pay scales; agencies navigate this by drafting contracts with clear deliverables and limiting government direction to contract-level (not worker-level) oversight

• §§ 37.200–37.203 — Advisory and assistance services: a specific category of services — management and professional support, studies and analyses, and engineering and technical services — that Congress has specifically targeted for oversight because of concerns about contractors performing inherently governmental functions; contracts for these services require specific justification and are subject to enhanced review; agencies must document that the services do not cross the line into inherently governmental activities (making policy decisions, directing government operations, binding the government to a course of action)

• §§ 37.500–37.503 — Inherently governmental functions: contracting officers must ensure that service contractors do not perform activities that are inherently governmental — defined as activities so intimately related to the public interest that they must be performed by federal employees; the definition encompasses: final decisions on procurements; determinations of agency policy; judgments affecting national security, tax collection, or criminal prosecution; conducting foreign relations; commanding military forces; the prohibition also covers "critical functions" that the agency relies on but that fall short of inherently governmental — agencies must maintain enough in-house expertise to manage and oversee contractors performing those functions, even if the work itself is contracted out; DOGE's 2025 review of contractor workforces specifically used this framework to evaluate which contractors should be terminated as potentially performing governmental functions

• Subpart 37.6 — Performance-Based Acquisition (§§ 37.600–37.603): the implementation subpart for PBA; a performance-based service contract must include: (1) a performance work statement or statement of objectives; (2) measurable performance standards; (3) a method of assessing contractor performance against those standards; and (4) performance incentives appropriate to the work (positive incentives for exceeding standards or penalties for failing to meet them); the contracting officer must prepare or have reviewed a quality assurance surveillance plan (QASP) describing how the government will monitor performance

Recent rulemakings: 79 FR 24213 (April 30, 2014) — significant update clarifying inherently governmental function definitions and advisory services thresholds; 62 FR 44815 (August 22, 1997) — addition of performance-based acquisition as the preferred method following the Federal Acquisition Streamlining Act.

How It Affects You

If you are a business or potential contractor: Contract type determines your cash flow profile and risk exposure. FFP rewards efficiency; CPFF pays costs but caps fee upside. IDIQ vehicles offer volume potential but require task order competition on each order. Getting on a GWAC or MAC is a multi-year investment that pays off in sustained order flow — the upfront costs are worth it for $1B+ ceiling vehicles.

If you work at a federal agency: Contracting officers must document the rationale for contract type selection in the acquisition plan. Using T&M without adequate justification exposes the program to OIG criticism and protest. Consider IDIQ/task order structures when requirements will recur but individual task scope is uncertain — it preserves flexibility without locking in T&M risk.

If you are a citizen, taxpayer, or journalist: The biggest cost growth risks are in CPAF and T&M vehicles on large service contracts. Award fee evaluations should be publicly available under FOIA. USASpending.gov shows contract type codes for all federal awards — filter by "R&D" NAICS codes and cost-reimbursement contract type to identify the highest-risk spending.

If you are a policy professional or advocate: DOGE's focus on T&M and cost-plus is not new — every administration since Reagan has pushed to shift toward FFP. The constraint is often requirements definition, not contractor preference. Programs with poorly defined requirements can't realistically use FFP; better requirements engineering upstream is the durable fix.

Recent Developments

• 2025 — DOGE review of civilian agency contracts flagged T&M and CPAF vehicles as primary targets for renegotiation or termination; OMB issued guidance directing agencies to justify any non-FFP contract type for new awards above $10M.
• 2024 — GSA's OASIS+ GWAC went live, replacing the $60B OASIS contract; it extended professional services IDIQ coverage to small businesses and significantly expanded ceiling values.
• 2023 — DoD increased FPIF use on major weapon system production contracts following a series of cost-overrun disputes on CPIF vehicles in shipbuilding.
• 2022 — GAO issued a bid protest decision limiting agencies' ability to use single-award IDIQs above $100M without heightened justification, reinforcing the preference for multiple-award competition.