What Should Urgent Care Centers Know About Flu Season Billing in 2026?
As of October 2026, the 2026-2027 respiratory season introduces updated billing requirements for urgent care centers performing flu, COVID-19, and RSV testing and treatment. CPT code 87812, which took effect January 1, 2026, is now the required code for combo COVID/flu rapid tests, replacing the previous practice of billing 87804 and 87426 separately. CMS has also published updated vaccine reimbursement rates for the 2026-2027 flu season, and modifier 25 rules remain a primary denial trigger when billing an E/M visit alongside rapid testing.
New combo test code in play. CPT 87812 covers rapid antigen tests that detect both influenza A/B and COVID-19 in a single device, and most major payers now require it for combo test kits.
Vaccine reimbursement rates updated. CMS published new payment allowances for influenza vaccine codes effective for the 2026-2027 season, with geographically adjusted rates available on the CMS Vaccines Pricing page.
Modifier 25 denials spike during flu season. Payers increase scrutiny on modifier 25 claims when E/M visits are billed alongside rapid tests, making documentation of a separately identifiable evaluation essential.
Billing Changes for the 2026-2027 Season
The 2026-2027 respiratory season brings several billing changes that urgent care centers need to implement before flu volume peaks. The most significant is the widespread adoption of CPT 87812, which the AMA approved effective January 1, 2026, to cover rapid antigen tests that detect both influenza A/B and COVID-19 using direct optical observation from a single test device. This code replaces the previous workflow of billing CPT 87804 (flu rapid test) and CPT 87426 (COVID rapid test) separately when using a combo test kit.
The distinction matters because most point-of-care combo test kits now on the market, including BinaxNOW COVID-19/Flu, FLOWFLEX PLUS, and CorDx Tyfast, are designed as single-device tests. Billing 87804 and 87426 separately for a single-device combo test is incorrect and will trigger denials from payers that have updated their edit logic. Urgent care centers still using the old two-code approach risk both denials and potential audit exposure.
CMS also published the 2026-2027 influenza vaccine payment allowances, with geographically adjusted rates available through the CMS Vaccines Pricing page. The vaccine administration codes remain G0008 (flu), G0009 (pneumococcal), and G0010 (hepatitis B), with the administration fee consistent across all three. For practices billing Medicare, the vaccine itself is covered at 100% with no beneficiary cost-sharing, but the administration code must be submitted correctly to avoid payment delays.
The most common billing issue we see providers run into during respiratory season is not the test coding itself. It is the interaction between the E/M visit, the rapid test, and modifier 25. When a patient presents with flu symptoms and the provider performs a rapid test during the same visit, the E/M service requires modifier 25 to be paid separately. Without proper documentation that the E/M was a separately identifiable service, the claim gets denied or the E/M portion gets bundled into the test.
How Should Urgent Care Centers Bill Combo Flu and COVID Tests?
The correct billing approach depends on the type of test kit your urgent care uses. As of October 2026, the AMA recognizes three distinct billing scenarios for respiratory rapid testing at urgent care centers.
If you use a single-device combo test that detects both influenza A/B and COVID-19 from one swab and one cartridge, bill CPT 87812 once. Do not bill 87804 and 87426 separately. The single-device combo test is a single analytic event, and 87812 is the correct representation. If you use separate individual test kits, one for flu and one for COVID, each run independently, bill CPT 87804 for the flu test and CPT 87426 for the COVID test. This is appropriate because two separate tests were performed. If you use a flu-only rapid test without a COVID component, bill 87804 alone.
| Test Scenario | CPT Code(s) | Common Error |
| Combo flu/COVID single device | 87812 | Billing 87804 + 87426 separately |
| Separate flu and COVID kits | 87804 + 87426 | Billing 87812 for two separate tests |
| Flu-only rapid test | 87804 | Adding 87426 when no COVID test was run |
| COVID-only rapid test | 87426 | Adding 87804 when no flu test was run |
| Flu test + strep test same visit | 87804 + 87880 | Omitting modifier 25 on E/M |
Source: AMA CPT 2026 code updates; CMS MLN Matters guidance. Always verify payer-specific requirements, as some commercial plans may lag behind CMS on code adoption.
Why Do Modifier 25 Denials Spike During Flu Season?
Modifier 25 denials are the single biggest revenue leak for urgent care centers during respiratory season. The pattern is predictable: patient volume surges, providers move quickly through visits, documentation gets thinner, and payers flag claims where the E/M visit does not appear to be separately identifiable from the rapid test.
The rule is straightforward. When you bill an E/M code (99202 through 99215) alongside a rapid test (87804, 87812, or 87426), you must append modifier 25 to the E/M code to indicate that the evaluation was a significant, separately identifiable service beyond the test itself. The documentation must support that the provider made medical decisions beyond just ordering and interpreting the test result.
In our experience matching providers with billing partners, the practices that avoid modifier 25 denials during flu season share a common pattern. They document the chief complaint, the clinical decision-making that led to ordering the test, and a separate assessment and plan that goes beyond the test result. A note that reads ‘patient has fever, ordered flu test, test positive, prescribed Tamiflu’ does not support a separately identifiable E/M visit. A note that documents the differential diagnosis, the examination findings that ruled out other conditions, and the treatment rationale does support it.
One question we hear constantly from practice managers is whether the 2027 modifier 25 payment reduction will compound the denial issue. The short answer is yes. CMS has finalized a payment reduction for services billed with modifier 25 starting in 2027, which means that each denied modifier 25 claim during flu season represents both lost revenue today and reduced revenue on approved claims going forward.
If modifier 25 denials and flu season billing errors are cutting into your revenue, a specialized billing partner can tighten your coding and documentation workflows before volume peaks. We match urgent care centers with billing companies that handle respiratory season surges.
How to Prepare Your Billing Before Volume Peaks
Respiratory season volume typically surges between late October and February. Urgent care centers that prepare their billing systems and staff before the surge avoid the costliest errors. Here is the priority list.
1. Update your charge capture to include CPT 87812. Verify that your EHR and practice management system recognize 87812 and map it correctly to combo test kits. If your system still defaults to 87804 + 87426 for combo tests, fix it now.
2. Confirm your CLIA certificate covers the tests you run. Point-of-care rapid tests require a CLIA certificate of waiver. If you have added new test kits since your last renewal, verify that your certificate covers them.
3. Train front desk staff on real-time eligibility verification. Flu season brings walk-in patients whose coverage status may have changed. Verify insurance eligibility at check-in for every visit, especially for Medicaid patients affected by recent eligibility changes.
4. Build modifier 25 documentation templates. Create note templates that prompt providers to document the separately identifiable E/M elements: chief complaint, examination findings, differential diagnosis, and a plan that goes beyond the test result.
5. Audit vaccine billing workflows. Verify that flu vaccine codes (90686, 90688, or the applicable formulation code) and administration codes (G0008 for Medicare, 90471 for commercial) are mapped correctly in your billing system.
6. Review your payer contracts for respiratory test carve-outs. Some commercial plans have specific reimbursement rates or prior authorization requirements for rapid respiratory testing. Check your top five payer contracts for any flu season-specific provisions.
Revenue Mistakes Urgent Care Centers Make During Flu Season
Providers often come to us after flu season ends, asking why their respiratory visit revenue was lower than expected. The answer is almost always one of the same three mistakes.
The first mistake is undercoding E/M visits during high-volume periods. When patient volume surges, providers rush documentation and default to lower-level E/M codes (99212 or 99213) even when the medical decision-making supports a higher level. A patient presenting with fever, cough, and shortness of breath where the provider evaluates for pneumonia, flu, and COVID, orders testing, and prescribes treatment typically supports a 99214 based on moderate-complexity medical decision-making. Coding it as a 99213 leaves $30 to $50 per visit on the table.
The second mistake is failing to bill separately billable services performed during the same visit. An urgent care visit for flu symptoms often includes an E/M evaluation, a rapid test, a nebulizer treatment (CPT 94640), or an injection (CPT 96372). Each of these is separately billable with proper documentation, but many practices bundle them into the E/M visit or skip billing the ancillary service entirely.
The third mistake is ignoring the ICD-10 diagnosis code updates that took effect October 1, 2026. The FY 2027 ICD-10-CM code set added 190 new codes, including updates to respiratory diagnosis categories. Using a deleted or revised code on a claim submitted after October 1 will trigger an automatic denial. Common respiratory diagnoses like J06.9 (acute upper respiratory infection) and J02.9 (acute pharyngitis) remain valid, but providers should verify any diagnosis code they have not used since before October 1.
Frequently Asked Questions
Use CPT 87812 for any single-device rapid test that detects both influenza A/B and COVID-19 in one cartridge. This code took effect January 1, 2026, and replaces the previous practice of billing 87804 and 87426 separately for combo test kits.
Yes. Bill the appropriate E/M code (99202 through 99215) with modifier 25 appended to indicate a significant, separately identifiable evaluation. The documentation must show that the provider performed an evaluation beyond simply ordering and interpreting the test result.
The influenza vaccine product code depends on the formulation (90686, 90688, or the applicable code for the specific vaccine). The administration code is G0008 for Medicare patients and 90471 for most commercial payers. CMS covers the vaccine at 100% with no beneficiary cost-sharing.
Yes. Point-of-care rapid tests including flu, COVID, and strep tests require a CLIA certificate of waiver. If your CLIA certificate does not cover the specific test kits you use, claims for those tests can be denied and the practice may face compliance risk.
Flu season runs from October through May, with the highest volume typically occurring between December and February. Urgent care centers should have their billing systems and documentation templates updated before late October to avoid errors during the initial surge.
CMS has finalized a payment reduction for services billed with modifier 25 starting in 2027. This means that the E/M portion of a flu visit where modifier 25 is used will reimburse at a lower rate than in 2026, making accurate coding and documentation even more important to protect revenue.
Next Steps
Update your charge capture for CPT 87812 and verify your CLIA certificate before flu volume peaks. If you are seeing modifier 25 denials on respiratory visits, review your documentation templates and consider working with a billing partner experienced in urgent care respiratory season workflows. For a detailed breakdown of rapid flu test billing, see our CPT 87804 billing guide. To understand how the upcoming modifier 25 changes will affect your 2027 revenue, read our coverage of the modifier 25 payment cut.
Flu season is when urgent care billing errors cost the most. We match urgent care centers with billing companies that specialize in respiratory season coding, modifier management, and denial prevention across all payers.
