Whether a relief veterinarian or relief technician is a W-2 employee or a 1099 independent contractor is not a decision your practice gets to make by putting a label in a contract.
The IRS applies its own common-law test, the Department of Labor applies a separate federal test, and some states add a third, stricter one — and in California, that state test treats a relief vet and a relief tech differently even when they're doing near-identical work.
The IRS test: three categories, no magic number
The IRS does not run classification as a checklist with a pass/fail score.
Its guidance groups the evidence into three categories: behavioral control — does the practice control or have the right to control what the worker does and how they do the job; financial control — are the business aspects of the job controlled by the practice, including how the worker is paid, whether expenses are reimbursed, and who supplies tools and equipment; and the type of relationship — is there a written contract or employee-type benefits, is the relationship expected to continue, and is the work a key part of what the practice does.
The IRS states plainly that there is no "magic" or set number of factors that decides it, and that no single factor controls the outcome on its own.
That is deliberately not a checkbox test — a practice cannot point to one favorable fact, like a signed 1099 agreement, and treat classification as settled.
Either the practice or the worker can request a formal determination by filing Form SS-8 with the IRS.
It is slow, but it produces an actual ruling rather than a guess — worth using where genuine doubt exists before a recurring relief arrangement gets built around the wrong answer.
The DOL applies a separate test — and its status is in flux
Classification for wage-and-hour purposes runs through a different federal agency and a different test.
The Department of Labor's Wage and Hour Division applies its own six-factor "economic reality" test under the Fair Labor Standards Act: opportunity for profit or loss depending on managerial skill; investments by the worker and the practice; the degree of permanence of the relationship; the nature and degree of control; whether the work performed is integral to the practice's business; and the worker's skill and initiative.
No factor is weighted in advance, and the DOL is explicit that this is not an ABC test.
That rule — finalized January 2024, effective March 2024 — is still the rule on the books.
But its enforcement status is genuinely unsettled: the Department stopped applying it in FLSA investigations as of May 1, 2025, reverting field staff to the older, pre-2024 framework for enforcement purposes while the 2024 rule's text stays formally in force.
A further proposal to replace the 2024 rule outright closed its public comment period in April 2026 and had not been finalized as of this writing.
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State tests can be stricter — California's ABC test, and its odd split
A practice can pass both federal tests and still fail its own state's.
A number of states apply an ABC test, which does not resemble either federal framework — it presumes employment unless the hiring business proves all three of: the worker is free from the practice's control and direction over the work, both under contract and in fact; the work performed falls outside the practice's usual course of business; and the worker is customarily engaged in an independently established trade of the same nature as the work performed.
Failing any single prong is enough to make the worker an employee as a matter of law — there is no weighing the factors the way the federal tests allow.
California is the sourced example worth knowing in detail, because it treats two relief roles differently. California Labor Code §2783(b) exempts a licensed veterinarian providing professional services from the state's ABC test, routing them instead to the older, more classification-friendly Borello multi-factor standard.
Veterinary technicians are not named anywhere in that exemption list.
A California relief veterinarian and a California relief technician doing comparable work in the same practice are, as a matter of statute, judged under two different legal tests — and the technician's is the stricter one.
Confirm your own state's test before assuming either the federal framework or California's applies to you.
Some other states apply their own ABC-style test to worker classification, and the details genuinely differ from California's.
What actually predicts how relief staff get classified
Across every test above, the same handful of facts keep mattering.
A relief hire who works a schedule the practice sets, uses the practice's equipment and systems, takes direction on how the job gets done day to day, and covers shifts on an open-ended, indefinite basis looks far more like an employee than a contractor — regardless of what the engagement letter calls it.
A relief hire who sets their own schedule across multiple practices, brings their own tools and licensing, is not economically dependent on any single practice, and is booked engagement by engagement looks more like a genuine contractor.
Most real arrangements sit somewhere between those two pictures, which is exactly why every test above weighs several factors rather than one.
W-2 relief is also a real, existing option, not a fallback.
Some relief staffing organizations directly employ veterinarians and place them into shifts, handling withholding and benefits themselves in exchange for a margin on the rate.
A practice weighing how to bring on relief coverage isn't limited to "employee, or 1099 you structure yourself" — a staffing organization's W-2 arrangement removes the classification question from the practice's side of the relationship entirely.
Before you classify a relief hire
The questions worth answering in writing before the first shift, not after a dispute or an audit raises them.
- Who sets the schedule — the practice, or the worker?
- Who supplies the equipment, scrubs, and systems used on shift?
- Is this an open-ended, recurring arrangement, or a defined engagement?
- Does this worker take shifts at other practices, or are you their only client?
- Have you confirmed which test your state applies — and whether it treats a relief veterinarian and a relief technician the same way?
- Would a Form SS-8 determination, or an employment attorney's review, resolve a genuine doubt before you scale the arrangement?
None of this needs to be adversarial.
Most relief relationships are exactly what they appear to be.
The point of asking is to catch the minority that aren't, before a pattern gets built around the wrong label.
If it's wrong, the exposure is the practice's
Misclassification consequences fall on the business, not automatically on the worker.
The IRS is direct about this: a practice that classifies a worker as a contractor with no reasonable basis for doing so can be held liable for that worker's employment taxes.
A "reasonable basis" defense can shield a practice from back taxes where one genuinely existed — but it is a defense to liability, not a determination that the worker actually was a contractor, and it does not apply automatically.
A misclassified worker can separately file Form 8919 to report their share of uncollected Social Security and Medicare taxes.
None of this is a reason to avoid relief staffing — it is a reason to get the classification right before a pattern of engagements makes it expensive to unwind. Relief work: 1099, W-2, and what a rate has to cover and W-2 vs 1099: the real math cover the same classification tests from the worker's side, plus what a compliant relief rate actually has to absorb once status is settled.
General information, not legal or tax advice