When a single cost, a piece of shared equipment, a staff member’s salary, or facility space, benefits more than one grant or cost objective, an institution cannot simply charge the full amount to one award. It must distribute, or allocate, that cost across every funding source and activity that benefits from it, in proportion to the benefit each one receives. That distribution methodology is cost allocation, and it is a distinct compliance discipline from setting an indirect cost rate or negotiating cost-sharing commitments, even though all three sit inside the same 2 CFR 200 cost-principles framework.
This guide covers the core regulatory standard, the allocation methods institutions actually use, and how a formal cost allocation plan documents the whole process for auditors.
The core standard: 2 CFR 200.405, allocable costs
Cost allocation is governed by 2 CFR 200 Subpart E, specifically 200.405, Allocable costs. The regulation’s core test is that a cost is allocable to a federal award or other cost objective if it is assignable to that award or cost objective in accordance with the relative benefits received.
A cost meets that standard if it satisfies one of three conditions:
- It is incurred specifically for the federal award, in which case it is charged there directly and no allocation is needed.
- It benefits both the federal award and other work of the recipient, and the benefit can be distributed in proportions that can be approximated using reasonable methods. This is the scenario cost allocation methodology exists to solve.
- It is necessary to the overall operation of the recipient and is only assignable in part to the federal award.
Where a cost benefits two or more projects or activities in proportions that can be readily determined, 200.405 requires it be allocated to those projects based on the proportional benefit. Where the proportions cannot be readily determined because of the interrelationship of the work involved, the regulation allows allocation on any reasonable, documented basis. The regulation also requires that all activities benefiting from an institution’s indirect costs, including unallowable activities and donated services, receive an appropriate allocation of those indirect costs, so that direct-cost-bearing awards are not left absorbing a disproportionate share.
Allocability is one of several conditions a cost must independently satisfy to be chargeable to a federal award at all, alongside being reasonable, necessary, consistently treated, and adequately documented under 200.403 and 200.404. A cost can be perfectly reasonable and still fail allocability if the institution cannot show, with a defensible method, how much of it belongs to a given award.
How cost allocation differs from indirect cost rates and cost sharing
These three concepts are frequently confused because they all appear in the same part of 2 CFR 200 and all involve dividing costs among funding sources, but they answer different questions:
- Cost allocation answers: how much of this specific shared cost belongs to this specific award, right now, based on relative benefit? It is a per-cost, per-transaction methodology.
- Indirect Cost Rate Proposal answers: what single negotiated rate should an institution apply, going forward, to recover its pooled facilities-and-administrative (F&A) costs across all its awards? This is a periodic, institution-wide negotiation with a cognizant federal agency, not a per-cost decision. In practice, indirect cost rate-setting itself depends on allocation methodology upstream, an institution has to allocate its own overhead costs (like a shared building) into indirect cost pools before it can build a defensible rate.
- Cost sharing answers: what portion of a project’s total cost will the institution (or a third party) fund itself, rather than charge to the sponsor? This is a commitment and compliance-tracking question, not a distribution-methodology question, and it applies even to costs that are never shared with any other award.
- The direct-cost-vs-indirect-cost distinction is about classification, whether a cost can be identified specifically with a particular award versus being incurred for common institutional purposes, not about the mechanics of dividing a shared cost across multiple benefiting objectives once it has been classified.
A research administrator can, in principle, get cost sharing and the indirect rate exactly right and still fail an audit on cost allocation, because allocation is about whether the underlying distribution of a specific shared cost is defensible, not just whether the resulting rate or match commitment looks correct on paper.
Common allocation methods
2 CFR 200.405 does not prescribe a single required method; it requires that whatever method is used produce a result that tracks relative benefit and can be documented and reproduced. In practice, institutions choose an allocation base suited to the type of cost being distributed. The most common methods are:
Proportional benefit / percentage-of-effort
Used heavily for personnel costs. When one employee splits time across multiple projects, salary and associated fringe benefits are allocated based on the actual percentage of effort documented for each project, consistent with the institution’s effort-reporting system. This is the most direct application of the 'relative benefit' standard: if a lab technician spends 40% of their time on Award A and 60% on Award B, the cost follows that same 40/60 split.
Square-footage / space-based allocation
Used for facility and occupancy costs, rent, utilities, building depreciation, when the underlying cost is genuinely a function of the physical space used. If two grant-funded labs share a floor and one occupies 1,600 square feet against the other’s 1,200, a $3,000 monthly space cost would reasonably be split roughly 57%/43% rather than evenly, because square footage is the allocation base that best reflects each project’s relative benefit from the space.
Usage-based allocation
Used for shared equipment and instrumentation, e.g., a core facility’s mass spectrometer or a shared server, where actual usage logs (machine hours, sample counts, compute time) provide a more defensible base than a flat headcount or effort split. This method is common wherever an institution can meter or log consumption directly, and auditors generally regard metered usage data as strong supporting documentation.
Transaction-count or headcount-based allocation
Used for administrative or service-unit costs where neither effort percentage nor square footage cleanly applies, for example, allocating a shared procurement office’s costs across departments by number of purchase transactions processed for each, or a shared IT helpdesk by number of users supported.
Whichever base is chosen, the requirement is the same: the base must have a demonstrable, logical relationship to the cost being allocated, be applied consistently across all benefiting cost objectives, and be documented well enough that an auditor can reconstruct the calculation. A method that happens to maximize recovery on a particular award, without a genuine benefit relationship to justify it, does not satisfy 200.405 even if the arithmetic is correct.
Cost allocation plans
Institutions with recurring shared costs, particularly larger universities, hospitals, and state or local government recipients, often formalize their allocation methodology in a written cost allocation plan (CAP). A cost allocation plan documents, for each category of shared cost, what the cost is, which cost objectives benefit from it, which allocation base is used, and how that base is calculated and updated. It functions as the institution’s standing, auditable answer to 'how did you arrive at this allocation,' so the reasoning doesn’t have to be reconstructed from scratch during a Single Audit.
A cost allocation plan is a narrower, more mechanical document than an Indirect Cost Rate Proposal, which builds a full negotiated rate from indirect cost pools and a distribution base under 2 CFR 200 Appendix III (for institutions of higher education) or the analogous appendices for other recipient types. A CAP can feed into that rate proposal, but many institutions also maintain allocation methodology for costs that never enter the indirect cost pool at all, shared direct costs split between two or more federal awards, for instance, where the allocation itself is the end product, not an input to a separate rate.
Good practice, reflected across sponsored-programs guidance from research universities, treats a cost allocation plan as a living document: the allocation bases (headcounts, square footage, usage logs) should be reviewed and updated on a set cadence, typically at least annually, so that the methodology continues to reflect actual relative benefit rather than a stale snapshot from when the shared cost arrangement began.
Why cost allocation is a common audit finding
Cost allocation failures are a recurring theme in Single Audit findings and OIG grant audits, not because the underlying rule is obscure, but because the documentation discipline it requires is easy to let slip in daily practice. The most common failure patterns are: allocating a shared cost using a base that has no logical connection to actual benefit (e.g., an even 50/50 split applied by default rather than by calculation); failing to update an allocation base after the underlying facts change (a lab’s square footage or an employee’s effort split shifts, but the allocation percentage doesn’t); and simply lacking contemporaneous documentation to support the base used, so the institution cannot reconstruct or defend the calculation when asked. Because allocability is a standalone condition a cost must satisfy under 200.405, a cost that is otherwise entirely reasonable and allowable can still be disallowed on audit if its allocation cannot be supported.
Frequently asked questions
What is the difference between cost allocation and an indirect cost rate?
Cost allocation is the methodology for dividing a specific shared cost among the awards or activities that benefit from it, based on relative benefit. An indirect cost rate is a single negotiated percentage an institution applies across all its awards to recover pooled facilities-and-administrative costs. Allocation methodology is often used upstream to build the indirect cost pools that feed into a rate proposal, but the rate itself is a separate, negotiated, institution-wide figure.
Does 2 CFR 200 require a specific cost allocation method?
No. 200.405 requires that whichever method is used produce results that reflect relative benefit and can be documented and applied consistently, it does not mandate FTE-based, square-footage, or usage-based allocation specifically. The institution selects whichever base most logically fits the cost type being allocated.
Who has to maintain a formal cost allocation plan?
2 CFR 200 does not universally require every recipient to maintain a standalone written cost allocation plan document, but any recipient with recurring shared costs across multiple awards needs a defensible, documented allocation methodology to survive a Single Audit, and larger institutions commonly formalize that methodology in a written CAP for exactly that reason.
Can an allocation method change over time?
Yes, and it generally should, when the underlying facts change (a change in square footage occupied, a shift in staff effort, new usage patterns on shared equipment). The requirement is that the current method be documented and consistently applied at the time each cost is allocated, not that the method be permanently fixed.
