What sets pathology billing services apart
Pathology billing services start from a requisition, not a check-in desk. The lab rarely sees the patient, so demographics, insurance and diagnosis codes arrive from the ordering office, and errors made there become the lab's denials. Fastora's certified billing and coding professionals work these claims for anatomic pathology groups, independent clinical laboratories and toxicology labs as part of our wider medical billing services.
Clinical lab billing also runs at volume: many low-dollar claims, each needing a valid order, a test covered by the lab's CLIA certificate and a diagnosis that supports medical necessity. A small gap repeats across thousands of claims, so the fix usually belongs upstream in the requisition or the charge build rather than in individual appeals.
Eligibility and requisition data without a patient visit
We run eligibility checks from the requisition as soon as a specimen is accessioned and request corrections from the ordering office while the details are still easy to confirm. The usual problems are missing subscriber IDs, a primary plan listed as secondary, and a Medicare Advantage plan billed as traditional Medicare.
Patients seldom recognize a lab's name on a statement. Lab statements should explain who the lab is, which provider ordered the test and how to reach the billing team, which helps reduce calls and disputes.
Prior authorization for molecular, genetic and drug testing
Many payers require authorization or pre-determination for molecular and genetic tests, sometimes through a lab benefit manager. The ordering clinician often holds that approval, so we confirm it exists and that the approved code matches the test performed before the claim goes out.
Some plans also cap definitive drug tests per year or expect a documented clinical reason before definitive testing. Those limits are checked against each payer's published policy for every client lab.
Pathology and lab codes and rules specific to this specialty
| Code | Descriptor (summary) | Billing note |
|---|---|---|
| 88300–88309 | Surgical pathology, gross and microscopic examination, levels I–VI | One unit per specimen; level set by specimen type |
| 88305 | Surgical pathology, level IV | Most frequently billed level; units match specimens in the report |
| 88342 | Immunohistochemistry, initial single antibody stain procedure, per specimen | First stain on each specimen |
| 88341 | Immunohistochemistry, each additional single antibody stain procedure, per specimen | Add-on to 88342 |
| 80305–80307 | Presumptive drug class screening, by method (direct optical observation, instrument-assisted, or chemistry analyzer) | Reported once per date of service |
| G0480–G0483 | Definitive drug testing, by number of drug classes (1–7, 8–14, 15–21, 22 or more) | Used by Medicare and many other payers for definitive testing |
| 36415 | Collection of venous blood by venipuncture | Billed by the entity that drew the specimen |
Modifier 26 reports a pathologist's professional component and TC the technical component when the two are billed separately. Modifier 90 flags a test sent to a reference laboratory, 91 a repeat clinical lab test needed for a new result, and QW a CLIA-waived test, which CMS requires on waived-test codes. Modifier 59 or the X modifiers belong only where separate specimens or sites support them.
Date of service
Under 42 CFR 414.510, the Medicare date of service for a lab test is generally the date the specimen was collected. Exceptions cover specimens stored more than 30 days before testing, the 14-day rule for certain tests ordered after a hospital discharge, and a separate rule for molecular pathology and some advanced diagnostic laboratory tests. The date decides whether the lab or the hospital bills, so we review it on referred specimens.
CLIA on the claim and surprise billing
CMS asks labs to include their 10-character CLIA number on all laboratory claims. A certificate of waiver covers only waived tests; moderate- and high-complexity testing needs a certificate of registration, compliance or accreditation. Under the No Surprises Act, pathology is one of the ancillary services for which out-of-network providers at in-network facilities cannot balance bill protected patients or ask them to waive those protections.
Documentation that supports lab and pathology claims
Each claim needs an order from a treating provider, a diagnosis taken from the order or the pathology findings, and a report that matches the codes and units billed. If the report lists four specimens and three stains, the claim should show the same.
Tests subject to national or local coverage determinations need a covered diagnosis. When Medicare coverage is uncertain, an Advance Beneficiary Notice signed before the test lets the lab bill the patient if Medicare denies, with the GA modifier on the claim.
Toxicology lab billing and payer policies
Toxicology lab billing draws close payer review. Presumptive screens are reported once per date of service no matter how many drug classes are screened. Definitive testing is coded by the number of drug classes, so the class count in the report must match the code billed.
Payers look for the clinical reason behind each definitive panel. Standing orders that test every patient for every class are a frequent audit target. Medicare contractors publish coverage determinations and billing articles on drug testing, and many commercial plans apply similar limits, so we map each lab's test menu to those policies and to the referring practices it serves, such as substance use treatment programs.
Common denials and how we prevent them
| Denial | Typical cause | Prevention step |
|---|---|---|
| Coverage terminated or wrong payer | Requisition carried old insurance | Eligibility run at accessioning |
| Missing or invalid CLIA | Number absent or test outside the certificate type | CLIA and certificate checked in the charge build |
| Medical necessity | Diagnosis does not support the test under an NCD or LCD | Diagnosis checked before submission; ABN workflow for Medicare |
| Units or frequency | Specimen, stain or drug class count exceeds the report or a payer limit | Units reconciled to the report |
| No authorization | Molecular test billed without lab benefit manager approval | Approval confirmed with the ordering office |
| Wrong billing entity | Date of service rules point to the hospital | Date of service review on referred specimens |
Every claim passes our pre-submission claim review before it is sent. Denials that still occur go to our lab denial follow-up, which corrects and resubmits or appeals with the order and report attached. Open claims are worked by payer in batches, since laboratory billing AR is high volume and low balance.
Credentialing for pathologists and laboratories
Pathologists enroll individually and reassign benefits to their group. Independent labs enroll as organizations and must keep CLIA, address and ownership details consistent across Medicare, Medicaid and commercial files, because a mismatch between the CLIA record and the enrollment record can lead to rejected lab claims.
Our credentialing and enrollment team tracks each application through a nine-stage process, from document collection and NPI and CAQH setup through payer applications and follow-ups to approval, so new pathologists and new lab locations are ready to bill.
How Fastora works with pathology groups and labs
Fastora works inside your existing EHR/PM system under the user access you grant, with no software to install and no hidden setup fees. Certified professionals handle coding, claim submission, payment posting, denials, AR follow-up and patient statements. You get a dedicated account contact, transparent dashboards, monthly performance reporting and a monthly review call.
Fees are quoted after a free assessment, and you can see how our pricing models work before you talk to us. To see where your lab billing services stand today, start with a free billing assessment.
Pathology and speech-language pathology billing
Pathology medical billing splits into two very different workflows. Anatomic and clinical pathology billing is date-of-service and panel-code driven — the work is getting the right CPT panel on the claim and keeping add-on codes supported by the lab report. Speech language pathology billing is the opposite shape: session-based, authorization-heavy, and tied to treatment plans and visit limits. As a pathology billing company, we run both workflows rather than forcing one onto the other. Related: speech therapy billing, free medical billing audit, pricing.