An internal float pool is a group of cross-trained employees a health system moves between units to cover gaps. Agency staffing brings in outside clinicians through staffing vendors. Float pools usually offer more continuity and familiarity with facility policies, while agencies offer more flexibility on volume, specialty, and timing. Most health systems use both, and the order in which shifts are offered, float pool first, then per diem, then agency, is what drives cost and fill speed.
Hard-to-fill shifts are the ones that expose the weak points in any staffing model: nights, weekends, short notice call-outs, and specialty units. This guide compares the two approaches, shows where each one struggles, and explains how float pool software helps leaders manage them as one system instead of two separate budgets.
What a float pool is
A float pool is a group of staff, usually nurses and other clinicians, who are not assigned to a single unit. They are cross-trained and credentialed to work in several areas, and managers send them where census or call-outs create a gap. Some health systems staff the pool with full-time employees, others with per diem employees, and many use a mix.
The appeal is control. Float staff already know the facility’s policies, charting systems, and escalation paths, so they need less orientation than an outside clinician on a first shift.
What agency staffing covers
Agency staffing means contracting with outside vendors who supply clinicians for a shift, a contract, or a travel assignment. Facilities lean on agencies when internal supply runs out: a seasonal census spike, a run of open night shifts, a specialty with too few local candidates, or a sudden wave of call-outs.
The appeal is flexibility. An agency network can add capacity quickly and can scale back down when demand drops, without the long-term commitments that come with growing an employed pool.
Float pool vs agency staffing at a glance
| Factor | Internal float pool | Agency staffing |
|---|---|---|
| Who employs the clinician | The health system | The staffing agency |
| Familiarity with the facility | Typically high | Varies, usually needs orientation |
| Speed of adding capacity | Limited by pool size and hiring | Can be fast through a vendor network |
| Flexibility on volume | Fixed unless the pool is expanded | Scales up and down with demand |
| Cost structure | Wages and benefits, no vendor markup | Bill rates that include agency margin and program fees |
| Credentialing | Managed by the facility | Shared between agency and facility |
| Best suited for | Predictable, recurring coverage gaps | Spikes, specialties, and last-minute needs |
Where each approach struggles
Float pool limits. A pool is only as useful as its size and skill mix. If float staff are cross-trained for too many units, competency can thin out. If the pool is too small, managers fall back on overtime or agency requests anyway. Float assignments can also feel unpredictable to staff, which affects retention if the process is not handled fairly.
Agency limits. Bill rates carry vendor margin and, in many programs, additional fees. Outside clinicians may need orientation, and continuity is harder when different people fill the same unit across weeks. In programs with tiered release, some agencies see a shift only after others have passed on it, which can slow down hard-to-fill requests. For more on how that works, see our guide to healthcare VMS vs MSP.
A tiered approach to hard-to-fill shifts
Rather than choosing one model, many health systems set a clear order for how an open shift is offered. A common sequence looks like this:
- Internal float pool: offer the shift to float staff first, since they are already credentialed and oriented.
- Per diem and internal incentive pools: open the shift to per diem staff and staff who opted in to extra shifts.
- Preferred agencies: release the shift to agencies the facility already works with.
- Wider vendor network: if the shift is still open, expand access to more agencies so hard-to-fill roles reach more candidates.
The last step matters most for roles that stay open. A vendor-neutral marketplace such as Lavaaro lets facilities and staffing agencies collaborate on hard-to-fill shifts, which widens the pool of candidates without adding a separate process for each vendor.
What float pool software should do
Float pool software connects the tiers above so managers are not working from spreadsheets and phone calls. When you evaluate options, look for the ability to:
- Match clinicians to shifts by license, unit competency, and availability
- Track credentials and flag expiring licenses before a shift is assigned
- Let float and per diem staff view and pick up open shifts from a mobile app
- Set rules for the order in which shifts are offered across float, per diem, and agency
- Show hours and spend across float, per diem, and agency in one view
- Report on fill rate, time to fill, and cancellations by unit
Questions to ask before changing your staffing mix
- What share of open shifts does the float pool fill today, and which units or shifts go unfilled?
- Which units rely on agency staff most, and are those gaps recurring or seasonal?
- How long does it take to move a shift from the float pool to agencies?
- Can we see float, per diem, and agency spend in one place?
- Are float staff cross-trained for the units where they are actually sent?
Tools worth considering
If you are comparing options for managing float pools and contingent labor, these are two to include in your review:
- Vars Health: a healthcare staffing and scheduling software platform. Its staffing and scheduling tools sit alongside float pool management, an applicant tracking system, onboarding, and timekeeping, which suits teams that want shift coverage and workforce records in one system.
- Lavaaro: a vendor-neutral marketplace where facilities and staffing agencies collaborate on hard-to-fill healthcare shifts.
Match any tool to your facility size, internal staffing model, and compliance requirements, and ask each provider for a demo before deciding.
Frequently asked questions
What is a float pool in healthcare?
A float pool is a group of cross-trained clinicians who are not tied to one unit and are assigned to units that need coverage, based on census, call-outs, or open shifts.
Is a float pool cheaper than agency staffing?
Often it can be, since there is no vendor markup, but it depends on wages, benefits, and how well the pool is utilized. An underused pool can cost more than expected.
Can a float pool include per diem staff?
Yes. Many health systems combine full-time float employees with per diem clinicians so they can flex capacity without relying only on agencies.
What is float pool software?
It is software that manages who is eligible to float, matches them to open shifts, tracks credentials, and shows coverage and cost across float, per diem, and agency staff.
When should a facility turn to agencies instead of floating staff?
Agencies make sense when the pool cannot cover a spike, when a specialty is in short supply internally, or when a shift is still open after internal options are exhausted.
