The US locum tenens market is large, roughly a nine-billion-dollar industry, and it looks crowded with agency names. The first thing worth knowing is that many of those names belong to a handful of parent companies, so the "choice" is narrower than it appears, and the more useful decision is about fit, specialty, and terms rather than brand. Here is an honest guide to the major agencies, how they actually relate to each other, what genuinely matters when you choose, and a checklist to run before you sign anything. You can and often should work with more than one agency.
Key takeaways
- Many agencies share a parent: CHG owns CompHealth and Weatherby; Jackson Healthcare owns LocumTenens.com and Jackson + Coker.
- The right agency depends on your specialty, preferred locations, and the kind of service you want.
- What matters most is malpractice type, credentialing speed, cancellation terms, and pay transparency.
- NALTO membership signals adherence to industry credentialing standards, though not every large agency is a member.
- Locum work typically pays 30 to 50 percent more than employed roles, with anesthesia and CRNA at the top.
How the market is actually structured
Before comparing agencies, understand who owns whom, because it explains a lot. CHG Healthcare is the largest group and includes CompHealth, Weatherby Healthcare and Global Medical Staffing. Jackson Healthcare owns LocumTenens.com and Jackson + Coker. AMN Healthcare owns Vista Staffing alongside its own locums division. Then there are large independents such as Barton Associates, Medicus Healthcare Solutions, Hayes Locums and Aya Locums. This matters because two "different" agencies may run on the same systems and inventory, and because working with one CHG brand does not really diversify you across CHG. So think in terms of parent groups plus independents when you build a shortlist.
The major agencies, honestly
Each has a genuine profile rather than a marketing one:
- CompHealth (CHG). One of the oldest, having pioneered US locum tenens in 1979, with broad national coverage across 100-plus specialties, deep hospital relationships, and full-service support including claims-made malpractice with tail. Recruiter quality can vary at its scale.
- Weatherby Healthcare (CHG). Known for specialist recruiting, particularly surgery and subspecialty medicine, and for strong credentialing and recruiter satisfaction, with a slightly more personal feel than the largest firms.
- LocumTenens.com (Jackson). Runs the most-visited locum job board plus a full-service agency, with a strong online dashboard for managing assignments, timesheets and credentialing. Good for browsing inventory and for scale.
- AMN Healthcare. One of the largest healthcare staffing companies, with institutional depth in big health systems and academic centers, coverage in hospital medicine, radiology, emergency medicine and surgery, and W-2 arrangements available for some. Strong compliance systems.
- Barton Associates. Covers all 50 states and territories across 100-plus specialties on a personal-recruiter model, and uniquely also staffs dental clinicians. Good for fast turnaround and a single point of contact.
- Vista Staffing (AMN). The specialist for federal and government-contracted facilities: VA hospitals, Indian Health Service and Department of Defense, where credentialing requirements are handled by a dedicated division.
- Medicus and Hayes Locums. Established independents; Hayes is physician-owned. Both offer full-service support and suit clinicians who prefer a mid-size, high-touch relationship.
- Aya Locums. Tech-enabled matching across multiple clinician roles, for those who prefer a platform-driven experience.
What actually matters when choosing
The differences that affect you are rarely the ones agencies advertise. Prioritize these:
- Malpractice type. Ask whether it is an occurrence policy or a claims-made policy, and if claims-made, whether tail coverage is included. This determines whether you are protected for claims made after the assignment ends, and it is the single most important contractual detail.
- Credentialing timeline. Ask for a realistic timeline and a named credentialing contact. Slow credentialing is the most common reason a start date slips.
- Cancellation terms. Assignments can be cancelled by the facility. Understand notice periods and whether you are compensated, because a cancelled block with no protection can cost you significantly.
- Pay transparency. Ask for an itemized breakdown: hourly or daily rate, plus who pays for travel, lodging, licensing and malpractice, and any call or overtime premiums. Compare total value, not headline rate.
- Licensing support and the IMLC. If you plan to work across states, ask how the agency handles multi-state licensing, and check whether your states participate in the Interstate Medical Licensure Compact, which streamlines licensing across participating states.
- NALTO membership and reputation. Membership of the National Association of Locum Tenens Organizations signals adherence to credentialing standards. Also check independent reviews and ask peers, including on physician forums, rather than relying on agency testimonials.
Notes by specialty and setting
Fit varies by what and where you practice. For emergency medicine and hospital medicine, the large national agencies carry deep inventory. For anesthesia and CRNA work, rates are the highest in the market, often several hundred dollars an hour, so shop aggressively. For rural and hard-to-fill assignments, premiums are higher and agencies with strong hospital relationships help. For federal or VA work, Vista's government focus is a genuine advantage. And if you might want a permanent role later, several agencies, including CompHealth and AMN, also handle permanent placement.
A checklist before you sign
Run through this every time: confirm the malpractice type and tail; get the credentialing timeline and a named contact in writing; read the cancellation clause and understand your protection; obtain an itemized pay and expenses breakdown; confirm who holds and pays for licensing; check references or peer reviews for that specific agency and recruiter; and never accept the first rate without asking what the facility is paying. Treat the contract as the product, because with locum work, the terms are where the value is won or lost.
Where iatroX fits
Locum work means walking into unfamiliar settings, and staying clinically sharp across varied assignments is part of the job. iatroX is a modest but useful part of that, with adaptive question banks and a Socratic tutor for board-relevant reasoning and keeping your knowledge current between assignments, plus free sample questions to try at iatroX. It is not a substitute for your usual point-of-care references on assignment; it is a way to stay reasoning-fit. For the wider picture of the tools doctors rely on, see how doctors find help online.
Frequently asked questions
Which is the best locum tenens agency for physicians? There is no single best one; it depends on your specialty, locations, and service preference. CompHealth and AMN offer broad national scale, Weatherby is strong for specialists, Barton for a personal-recruiter model, and Vista for federal and VA work.
Are the big locum agencies all owned by the same companies? Several are. CHG Healthcare owns CompHealth, Weatherby and Global Medical Staffing; Jackson Healthcare owns LocumTenens.com and Jackson + Coker; AMN owns Vista. Barton, Medicus, Hayes and Aya are large independents.
What malpractice coverage should a locum physician have? Confirm whether it is an occurrence or claims-made policy, and if claims-made, whether tail coverage is included, since that protects you for claims made after the assignment ends. It is the most important contractual detail to check.
How much more do locum physicians earn? Typically 30 to 50 percent more than employed roles, varying widely by specialty, geography and urgency. Anesthesiologists and CRNAs command the highest rates, often several hundred dollars per hour.
Can I work with more than one locum agency? Yes, and many physicians do, because inventory and rates differ. Just track your credentialing and commitments carefully, and remember that different brands under the same parent may share inventory.