Should you bring your toxicology testing in-house? For some practices, the benefit of converting reference lab invoices into revenue outweighs the lab start-up cost. For others, documentation missteps end up costing them more than it’s worth. In this blog, we’re going to look at both scenarios – and help you decide what makes sense for your own practice.
Every practice that considers bringing lab testing in-house runs the same financial calculation: convert the reference lab invoice into revenue the practice keeps instead. One academic laboratory documented $978,690 in net savings over three years after doing exactly that.
Several other practices ran the same math and still ended up owing millions in federal settlements, because they couldn’t prove after the fact why they’d ordered the tests they billed for.
If you’re thinking about bringing toxicology lab testing in-house, ask yourself the following questions before you buy an instrument:
1. Does Your Testing Volume Clear the Real Breakeven?
A phased rollout gives your practice time to course-correct before the full cost hits, and it typically follows the same order:
- Staffing and platform selection
- Screening
- Confirmatory testing (once volume supports it)
Plan for that sequence to play out over the better part of a year. Compress it into a few months instead, and you’re paying a technical supervisor’s salary and covering instrument costs before you actually know whether your patient volume is enough to justify them.
Breakeven Volume
Breakeven here means the volume where running tests in-house costs less overall than sending them to a reference lab. That means counting instrumentation, consumables, quality control runs, and a technical supervisor’s salary, not just the price of a single test kit.
Below that volume, a practice ends up paying more per test when running it in-house than it would have paid a reference lab, because there isn’t enough volume to spread those fixed costs.
2. Can You Defend Every Definitive Test Order in Writing?
The Documentation Gap
Toxicology testing runs on two tiers, and whether you can show why a specific result moved from one to the other is what separates a defensible test order from a costly one:
- Presumptive testing typically screens for a drug class using immunoassay technology, though some labs also use LC-MS/MS for screening, and turnaround time depends on the platform and workflow.
- Definitive testing uses LC-MS/MS to identify specific compounds at nanogram-per-milliliter concentrations, and is what payers require before they’ll reimburse a confirmed result. It doesn’t have to follow a presumptive result: a practice can order it directly based on a patient’s history, risk profile, prescribed medications, or the limits of the available screening method.
Every order a practice bills for requires documentation of medical necessity for that specific patient, whether it’s a presumptive screen, a definitive test ordered on its own, or a definitive test following a presumptive result. That documentation, not a fixed sequence between the two tiers, is what regulators are checking for.
Recent Settlements
Federal enforcement has been active in this space for years:
- Advanced Pain Care, an Austin practice, settled for $13,625,000 in December 2025. CMS doesn’t universally prohibit same-day presumptive and definitive testing when both are medically necessary and documented; NCCI briefly restricted same-day billing in 2023, but CMS later withdrew those restrictions. The actual issue was ordering both tests concurrently without first reviewing the presumptive result to determine why the definitive test was needed.
- Two Texas physicians paid $3.9 million in early 2025 over blanket testing orders that weren’t tailored to individual patients.
- A Maryland pain practice paid $980,000 over a similar pattern of excessive testing without individualized medical necessity.
They lacked proper medical-necessity documentation and testing orders tailored to each individual patient, three different failures with one shared fix: a documented, patient-specific reason behind every order.
3. Does Your Staffing Plan Survive One Person Leaving?
Staffing and CLIA Personnel Requirements
A new testing program depends on someone qualified to run and interpret results, and that isn’t an easy hire. Confirmatory LC-MS/MS testing typically falls under CLIA’s high-complexity category, which requires a qualified technical supervisor on record and staff specifically trained on that platform.
Chemistry and toxicology departments also carry among the highest vacancy rates of any lab department in the country, so that hire is competitive before you even factor in the specialized training.
What Happens When That Person Is Out
A practice with only one qualified person has a single point of failure. If that person is out for a week, sample turnaround slows, and quality control reviews pile up. Scheduled proficiency testing, the periodic blind samples CLIA requires labs to run to confirm their results match other labs’, can get missed entirely too.
Cross-training a second staff member on the platform and documenting procedures well enough for someone else to follow them are what keep a single absence from stalling the whole program.
4. Is Your CLIA Certificate Built Before the Instrument Arrives?
Certificate Types
Getting the right CLIA certificate takes longer than most practices plan for, and it has to be in place before patient testing begins, not before the instrument itself arrives. Installation, staff training, and method validation typically run concurrently with that certificate process, not after it’s already secured.
Bringing confirmatory testing in-house means applying for a Certificate of Registration, which permits moderate- and high-complexity testing while the lab awaits its first survey. Afterward, your in-house lab needs to maintain a Certificate of Compliance or Accreditation.
Certificate Obligations
That certificate comes with two obligations that don’t pause for a busy month:
- Biennial inspections
- Enrollment in a formal proficiency testing program under CLIA ’88
Proficiency testing compares the lab’s results on blind samples with those of peer laboratories running the same test. A practice ready to go in-house with its toxicology testing has already mapped its proficiency testing enrollment and inspection cycle before the instrument shows up.
5. Do You Have a Verification and Service Plan for the Instrument?
Verification vs. Validation Under CLIA
An LC-MS/MS platform down for even a few days has to come back either verified or validated before testing resumes, and which one applies depends on what’s running on it. Under 42 CFR §493.1253, an unmodified FDA-cleared instrument running an FDA-cleared method needs verification against the manufacturer’s stated performance specs.
A modified method or a laboratory-developed panel, common in custom toxicology testing, requires validation instead: the lab establishes and documents its own performance specs rather than relying on the manufacturer’s. Confusing verification with validation is an easy way to under-document a laboratory-developed method.
Service Requirements
Under 42 CFR §§493.1254–493.1255, a move, a repair, a part replacement, or a software update triggers a documented assessment, along with whatever verification or performance testing that assessment calls for. That assessment doesn’t have to be a full revalidation, since the lab director decides the extent on a case-by-case basis.
Getting that right consistently is harder once more than one vendor has touched the instrument, since whoever makes that call needs the full repair history to determine what a given change requires.
READ MORE: Equipment Compliance Issues Most Mass Spec Labs Keep Missing
Conclusion
Volume, documentation, staffing, certification, and instrument planning are the decisions a practice has to get right before it invests in an in-house testing program, and missing any one of them is how a program that should pay for itself ends up in a settlement instead. Working through all five alone is possible, but it’s also where many practices lose time or make mistakes.
ILS’s Lab Management Services team handles volume, staffing, certification, and documentation: evaluating whether a testing model actually fits a practice’s volume, setting up CLIA and personnel requirements, and building the SOPs that keep documentation defensible once the program is running. The clinical decision behind each test order still belongs to the provider. What LMS builds is the paperwork around that decision, templates and workflows that make it straightforward to document why a test was ordered for that patient, so the decision holds up if a regulator asks.
Instrument planning is the one piece LMS doesn’t own directly, and it’s where ILS’s service side takes over. A different vendor handling every repair means nobody holds the full verification and service record, and that gap is exactly what shows up during an inspection. ILS runs under a single contract, so a repair and its record come from the same place.
If your practice is weighing an in-house testing program and wants help building the documentation and workflows behind it, get in touch.