SOW vs contingent labor in a VMS: how programs decide, how SOW work flows, and what changes for agencies
On this page
- What is the difference between SOW and contingent labor?
- How does a program decide which one to use?
- How does SOW work move through a VMS?
- Why do programs police hourly labor disguised as SOW?
- Does the program fee apply to SOW work?
- What does an agency have to change to bid SOW work?
- A checklist before you bid a SOW in a VMS
- Questions people ask
In a VMS, contingent labor (staff augmentation) means a worker the client directs and pays for by the hour, ordered against a rate card. A statement of work (SOW) buys a defined result, a project or an ongoing service, for a fixed price or milestone payments, and the supplier manages its own people to deliver it. Public programs draw the line plainly: Virginia's IT contingent labor policy says "all work performed on an hourly basis is considered a staff augmentation engagement, NOT an SOW-based engagement" (VITA ITCL policy, 2023 revision, checked October 2026). Most VMS platforms handle SOWs in a separate services module with its own bids, milestones and approvals.
This page explains how programs decide between the two, how SOW work moves through a VMS, why programs police hourly work dressed up as SOW, whether the program fee applies, and what an agency has to change to bid. For the staffing side of the comparison, see what is staff augmentation; for the VMS modules, what is a VMS in staffing.
What is the difference between SOW and contingent labor?
Virginia's one-page guide for agencies using its contingent labor contract compares the two side by side (Staff Augmentation or SOW: How to Decide?, VITA). Summarized:
| Question | Contingent labor (staff augmentation) | Statement of work |
|---|---|---|
| What is bought | A resource, often for a short-term need or a skill the client lacks | A project or service with defined deliverables |
| Who directs the work | The client's manager supervises the worker | The supplier manages all project activities; the client manages delivery against the SOW |
| How it is priced | Hours worked times the bill rate | A fixed amount when work products are delivered and accepted, or a fixed monthly fee for operations and maintenance |
| What is defined up front | The role; the specific work may not be | Deliverables, acceptance criteria and other terms |
| Tools and equipment | Provided by the client | Provided by the supplier |
| Supplier's obligation | Provide a qualified person who works as directed | Deliver what the SOW says, however many people that takes |
The same guide lists the questions a manager should answer first: is the need a resource or a project, do you have staff to manage the work, can you document the requirements, is a company needed or just people, and is there a fixed budget.
How does a program decide which one to use?
The deciding test is control. If the client will direct the person day to day, it is staff augmentation, whatever the paperwork says. If the client can describe the result and accept or reject it, a SOW fits. Federal buyers use a similar test: the Federal Acquisition Regulation describes a personal services contract as one that creates an employer-employee relationship, marked by "relatively continuous supervision and control," and lists warning signs such as on-site work, government-furnished tools and a need lasting beyond a year (FAR 37.104).
Programs that allow both usually say so in the contract:
- Maine's IT staff augmentation contract, run by Knowledge Services on its dotStaff VMS, also allows "milestone-based, deliverable-based and/or fixed fee" SOW projects through the VMS (State of Maine).
- Virginia caps SOWs at $3 million through its program and asks agencies to size each project in one of three tiers (up to $300,000, $1 million or $3 million) so smaller firms can compete (VITA policy, linked above).
- Tennessee's draft MSP contract for its 2026 procurement defines projects-based work as milestone or fixed-bid deliverables "not billed on an hourly basis" and requires the MSP to deliver at least three project quotes for each SOW (Tennessee pro forma contract, RFP 32110-38726).
How does SOW work move through a VMS?
SAP Fieldglass describes its services workflow in steps that most programs share (SAP Learning, exploring the services workflow):
- Requirements. The hiring manager enters the project: tasks, timeline, worker roles and budget. Virginia calls this a statement of requirements and asks for outcomes, not effort.
- Bids. The program releases it to qualified suppliers, who respond with a price, approach and team. The client evaluates and awards.
- The SOW and its characteristics. The awarded SOW lists the fees, milestones or deliverables the supplier must complete. It routes through the buyer's approvers.
- SOW workers. After acceptance the supplier adds people to the defined worker roles, which may need their own approvals. In Virginia, the same onboarding as staff augmentation applies, including background checks and E-Verify.
- Delivery. On time-and-materials SOWs, workers submit time sheets. On fixed-price SOWs, the supplier marks milestones complete.
- Acceptance and invoice. The buyer reviews and approves each completed item; Fieldglass can then generate the invoice automatically, or the supplier creates it.
- Changes and close. Changes go through written change orders. Virginia does not allow change orders to raise the original SOW price by more than 50%.
Why do programs police hourly labor disguised as SOW?
A manager who wants a particular contractor, at a rate above the card, has an incentive to call the engagement a SOW. Programs push back because it undoes the controls the program exists for:
- Rate card and competition. A SOW priced as hours times a rate, for one named person, skips the rate card and the competitive release. Virginia discourages named suppliers and requires agency head approval to use one.
- Supervision and co-employment. If the client directs the SOW workers like its own staff, the work is staff augmentation in substance, with the joint-employment exposure that comes with it; see joint employer liability for staffing agencies.
- Worker classification. SOWs are where 1099 contractors tend to appear. Tennessee's definition of projects-based work names independent contractors explicitly, which is all the more reason to classify them correctly; see worker misclassification for staffing agencies.
- Reporting. Hours hidden in a fixed fee disappear from tenure limits and headcount reports.
Signs that a "SOW" is really staff augmentation:
- The price is a named person's hours times a rate, with no deliverable.
- The acceptance criterion is "time sheets approved."
- The client's manager assigns tasks daily and runs the worker's performance conversations.
- The SOW renews every quarter with the same person and no new scope.
Does the program fee apply to SOW work?
Sometimes, and you need to know before you price. SAP Fieldglass has separate settings, "MSP Calculation for Contingent" and "MSP Calculation for Services," so a program can charge the fee on one module and not the other (SAP Learning, defining MSP fees). Tennessee's draft contract does charge it on SOWs: its SOW template says the sub-vendor's milestone payments "will be the agreed upon amount less the X% MSP Fee" (pro forma, linked above).
On a fixed price, a fee you forgot is a direct cut to margin you cannot bill back. Ask the program office three things in writing: does the fee apply to SOW milestones, to time-and-materials SOW hours, and to SOW expenses. What a fee does to a capped hourly rate is worked through in VMS fees for staffing agencies; the bookkeeping is in how staffing agencies record VMS fees.
What does an agency have to change to bid SOW work?
| Area | Staff augmentation habit | What a SOW needs instead |
|---|---|---|
| Pricing | Pay rate plus markup | Estimated effort, a risk margin and the program fee, priced as milestones |
| Scope | Whatever the manager assigns | Written deliverables and a change order for anything new |
| Acceptance | Approved time sheets | Acceptance criteria and a testing window agreed before signature |
| People | Submit candidates for one req | A team with a lead; key personnel named if the SOW requires it |
| Supervision | The client directs the worker | Your lead directs your people; the client reviews results |
| Cash | Weekly billing from approved hours | Payment only after acceptance, so you fund payroll in between |
| Insurance | Workers' comp, liability, EPLI | Often professional liability too; see errors and omissions insurance for recruiters |
Example (all figures invented): a data migration SOW estimated at 600 hours of work your people cost you $62.00 an hour fully burdened, so $37,200. Add a 15% contingency for estimating risk ($5,580) and a target gross margin, and price it at $54,000 in three milestones. If the program charges a 1% fee on milestone payments, you receive $53,460. If the work actually takes 760 hours, your cost is $47,120 and the margin left is $6,340, about 12% of what you received, instead of the roughly 30% the estimate promised. That is the risk the client is paying you to carry.
A checklist before you bid a SOW in a VMS
- Is this really a deliverable, or a person by the hour? If the latter, ask for it to be released as staff augmentation.
- Do we have the fee terms for services in writing?
- Are the acceptance criteria and testing period specific enough to get paid?
- Who on our side directs the work, and is the client comfortable not supervising our people?
- Can we fund payroll until the first milestone is accepted and paid?
- Are the SOW workers onboarded, classified and insured exactly as the program requires?
This is general information about how programs operate, not legal advice; for classification and co-employment questions on a specific engagement, ask employment counsel.
Questions people ask
What is the difference between SOW and contingent labor?
Contingent labor, often called staff augmentation, is a worker the client directs and pays for by the hour. A statement of work buys a defined result, such as a project deliverable or a set of services, usually for a fixed price or milestone payments, and the supplier manages its own people to deliver it. Virginia's contingent labor policy puts it bluntly: work performed on an hourly basis is staff augmentation, not an SOW.
Does the MSP fee apply to statement of work engagements?
It depends on the program. SAP Fieldglass has separate MSP fee settings for contingent and services programs, so a program can charge on one, both or neither. Tennessee's 2026 draft MSP contract applies its fee to SOW work too: the sub-vendor's milestone payments are the agreed amount less the MSP fee. Read the fee clause for the services side before you price a bid.
Why do VMS programs stop hourly work from being run as a SOW?
Because it bypasses the program's controls. Hourly work labeled as a SOW can avoid the rate card and competition, can escape the contingent worker tenure and onboarding rules, and puts a client manager in day-to-day control of people the supplier is supposed to manage, which raises co-employment and misclassification questions. Public programs such as Virginia's write the rule into policy.
What does a staffing agency need to bid SOW work through a VMS?
A fixed price built from estimated effort plus a risk margin, acceptance criteria you can actually meet, a change order process, named key personnel if the SOW requires them, the insurance the program asks for, and enough cash to carry the work until milestones are accepted and paid. The workers are still your employees, onboarded under the program's rules.