Per diem scheduling works by matching a pool of qualified workers to individual open shifts as staffing gaps come up, rather than assigning fixed weekly rotations. The employer identifies a need, pushes the opening out to everyone in the per diem pool, and the first person to claim it gets the shift. Nothing is guaranteed on either side: no shift is promised for any specific period, and you are not obligated to accept every offer. In exchange for that unpredictability, per diem workers often earn a higher hourly rate and keep control over when they work.
How Availability Submissions Work
You start by entering your availability into whatever scheduling system your employer uses. That might be a dedicated staffing portal, a workforce management app, or a shared spreadsheet at smaller organizations. You mark the dates you cannot work (sometimes called block-out dates) so the system does not flag you for shifts on those days, and you indicate preferences like shift length and time of day. Most employers want this information two to four weeks before a new scheduling cycle begins.
Accuracy matters more than people realize. Once your availability is logged, it becomes the baseline for every offer you receive. Mark yourself available on a day you cannot actually work and you will get offers you have to decline, which can count against you in systems that track acceptance rates. Forget to block out a day and you may be penalized for ignoring an offer that lands on it.
How Open Shifts Get Filled
After availability is logged, the employer matches staffing gaps against the pool and pushes open shifts to everyone who qualifies. Notifications usually arrive by mobile app, automated text, or email, and the message shows the date, time, location, and often the department or role. Speed matters. Most systems operate first-come, first-served, so if three nurses are available for one overnight shift, whoever taps “Confirm” first gets it.
Claiming a shift means following whatever prompt the system provides: tapping a button, replying with a code, or calling a coordinator back within a set window. For last-minute vacancies from sick calls or emergencies, a coordinator may phone workers directly rather than waiting for app responses. Once you accept, the system generates a confirmation. That electronic record is your formal assignment and your proof of the work agreement for that shift.
Staying on the Active Roster
Per diem positions are not permanent the way regular jobs are, and most employers set minimum activity thresholds to keep you on the roster. A common floor is something like two shifts a month, or a set number of hours over a rolling quarter. Drop below that and you risk what is sometimes called administrative termination, where you are removed from the active pool for inactivity. Employers typically audit participation at least twice a year.
In fields that require professional credentials, scheduling access is also tied to keeping those credentials current. If a certification lapses, most systems automatically lock you out of claiming shifts until you upload updated documentation and HR verifies it. The system treats an expired credential the same way it treats someone who quit: you disappear from the available pool until the issue is resolved.
Pay Premiums and Overtime
Per diem workers often earn a higher hourly rate than full-time staff doing the same job. The premium compensates for the lack of benefits like health insurance, paid time off, and retirement contributions. Industry surveys have found the average premium runs around 14 to 15 percent above the base wage, though it varies widely and roughly half of facilities that use per diem staff pay no premium at all. Ask about it before accepting a position.
Overtime rules apply to per diem workers exactly as they apply to anyone else covered by the FLSA. Work more than 40 hours in a single workweek and the employer owes time-and-a-half for the extra hours. The wrinkle for per diem staff is that you may work at different pay rates in the same week, such as a standard day shift and a higher-paid weekend shift. In that case, your overtime rate is calculated as a weighted average: total earnings for the week divided by total hours, multiplied by 1.5 for any hours over 40.1eCFR. 29 CFR 778.115 – Employees Working at Two or More Rates Each workweek stands alone. Your employer cannot average hours across two weeks to avoid paying overtime.2eCFR. Part 778 – Overtime Compensation
Shift Cancellations and On-Call Pay
Employers can cancel a scheduled shift if demand drops, a situation commonly called “low census” in healthcare. Most organizations try to give at least 90 minutes to two hours of notice, but no federal law mandates advance warning for cancellations. The FLSA only requires payment for time actually worked, and there is no federal reporting-time-pay rule. Some states and cities do require employers to pay a minimum number of hours (typically two to four) when you show up for a shift that then gets cancelled, and a handful of jurisdictions have predictive scheduling laws that add penalties for last-minute changes. Coverage varies, so check your state’s labor rules.
On-Call Time
On-call arrangements are common for per diem staff, and whether the on-call hours are paid depends on how restricted you are. Federal regulations draw a clear line: if you have to stay on the employer’s premises or so close that you cannot use the time for your own purposes, that time counts as work.3eCFR. 29 CFR 785.17 – On-Call Time If you only need to leave a phone number and are otherwise free, you generally are not working for FLSA purposes.4U.S. Department of Labor. Fact Sheet #22: Hours Worked Under the Fair Labor Standards Act (FLSA)
The gray area is on-call at home with heavy restrictions, like a 15-minute response requirement or a no-alcohol rule. The more constraints the employer places on your freedom, the stronger the argument the hours are compensable. Courts evaluate these situations case by case.
Health Insurance, Retirement, and Sick Leave
Per diem workers are often told they do not qualify for employer-sponsored health insurance, and in the short run that is often true. But the Affordable Care Act catches a lot of per diem workers by surprise. Employers with 50 or more full-time equivalent employees must offer coverage to anyone who averages 30 or more hours a week, which works out to 130 or more hours a month.5Internal Revenue Service. Identifying Full-Time Employees
Because per diem hours fluctuate, the IRS lets employers use a “look-back measurement period” to figure out whether a variable-hour worker crosses that threshold. The employer picks a window between 3 and 12 months and tracks your average hours across it. If the average hits 30 or more, the employer must offer you coverage during a subsequent “stability period” of equal length, even if your hours drop later. Failing to offer qualifying coverage triggers penalties under IRC Section 4980H.6Office of the Law Revision Counsel. 26 U.S. Code 4980H – Shared Responsibility for Employers Regarding Health Coverage
Retirement plan access has a similar wrinkle. Under ERISA, a plan can require one year of service (a 12-month period with at least 1,000 hours) and age 21 before you can participate.7Office of the Law Revision Counsel. 29 U.S. Code 1052 – Minimum Participation Standards Many per diem workers never reach 1,000 hours, which is why they get excluded. The SECURE 2.0 Act changed that. Long-term, part-time employees who work at least 500 hours per year for two consecutive 12-month periods must now be allowed into their employer’s 401(k), even if they never reach 1,000 hours.8Internal Revenue Service. Additional Guidance With Respect to Long-Term, Part-Time Employees The final IRS regulation applies to plan years beginning on or after January 1, 2026.
Paid sick leave has no federal mandate, but more than a dozen states plus Washington, D.C. have their own. Per diem workers generally qualify the same as any other employee. The common accrual rate is one hour of paid sick leave for every 30 hours worked, though some states use 35 or 40. Your pay stubs or scheduling portal should show your balance; if not, ask HR.
Why Per Diem Workers Are Usually W-2 Employees
A common misconception is that per diem workers are independent contractors who receive a 1099. In most cases they are W-2 employees. The IRS looks at three factors: whether the employer controls how the work is done, who handles financial matters like tools and reimbursement, and the nature of the relationship.9Internal Revenue Service. Independent Contractor (Self-Employed) or Employee?
Per diem workers almost always fail the independent contractor test. The employer sets the schedule, dictates procedures, provides equipment, and assigns the work location. That is employee status by any reasonable reading of the IRS criteria, which means income tax withholding, employer-side Social Security and Medicare contributions, and a W-2 at year end. An employer classifying per diem staff as 1099 contractors while controlling the details of the work is misclassifying them, and the tax exposure runs both ways.