CPT 87798: The Code Payers Stopped Trusting
Policy analysis · Pinnacle Services Corporation · Research current as of March 2026; the reimbursement timeline was updated in September 2026.
Independent clinical laboratories billing CPT 87798 now face denial rates approaching 27.5% on molecular claims, with payers on every side — Medicare, commercial and Medicare Advantage — tightening coverage through anti-unbundling enforcement, restrictions on not-otherwise-specified codes, and audit programs. The code's "not otherwise specified" nature has become its greatest liability: payers cannot tell what test was performed, and the uncertainty cascades into experimental-and-investigational denials, medical-records requests and bundling downgrades to 87801. The reimbursement rate, about $35 a unit, has been frozen since 2021 by successive Congressional delays to the PAMA cuts; that reprieve expires on January 1, 2027, when reductions of up to 15% a year are scheduled to resume. Laboratories that do not adapt their coding, documentation and post-adjudication recovery to this environment stand to lose revenue on one of molecular diagnostics' most widely billed codes.
The NOS problem is now the central vulnerability
CPT 87798 describes "infectious agent detection by nucleic acid (DNA or RNA), not otherwise specified; amplified probe technique, each organism." That final phrase — not otherwise specified — is what makes the code uniquely problematic. When a payer receives a claim for 87798, it has no visibility into which organism was tested, creating a trust deficit that cascades into denials across every category.
The most frequently reported denial codes tell the story. CO-50 and CO-96 (non-covered, experimental) dominate, particularly from Cigna, Aetna and several Blue Cross Blue Shield plans that categorically flag NOS codes as investigational. CO-97 and CO-236 appear when payers bundle 87798 with other molecular codes or enforce NCCI procedure-to-procedure edits. CO-11 and CO-151 surface on multiple-unit claims exceeding the medically unlikely edit threshold of 13 units per date of service (with an adjudication indicator of 3, meaning clinical documentation can override the edit on appeal). Remark codes N35, N386, N425, N657 and M77 round out the landscape, flagging everything from LCD non-compliance to missing organism identification.
Code | Meaning | What triggers it on 87798 |
|---|---|---|
CO-50, CO-96 | Non-covered, not medically necessary | NOS code flagged as experimental by Cigna, Aetna and BCBS plans |
CO-97, CO-236 | Bundling, procedure-to-procedure edit | NCCI edits; payers downcoding to 87801 |
CO-11, CO-151 | Frequency, medically unlikely edit | Multiple units above the MUE of 13 (adjudication indicator 3) |
N386, N657 | Missing information, LCD non-compliance | No organism specified; ICD-10 mismatch with the LCD |
M77 | Medical-records request | Payer cannot determine the test from the NOS code |
XiFin's 2024 Payor Denial Impact Report, based on more than 20 million claims with 2023 dates of service, found that molecular laboratories had the highest denial rate of any laboratory segment, at 27.5% — roughly double the 13.6% rate for clinical laboratories overall. Up to 40% of molecular claims are denied on first submission. Yet an estimated 65% of claim denials are never appealed.
MolDX policies tightened again in mid-2025
The most consequential Medicare coverage framework for 87798 is the MolDX molecular syndromic panels LCD family, administered by Palmetto GBA across four contractor jurisdictions covering 28 states. The major MolDX LCDs were revised effective July 3, 2025, with the corresponding billing and coding articles updated effective October 1, 2025 to incorporate the annual ICD-10 changes.
LCD | Contractor | Revision | Billing article |
|---|---|---|---|
L38988 | Palmetto GBA (JJ, JM) | 07/03/2025 | A58710 (rev. 10/01/2025) |
L39001 | Noridian (JE) | 07/03/2025 | A58720 (rev. 10/01/2025) |
L39003 | Noridian (JF) | 07/03/2025 | A58726 (rev. 10/01/2025) |
L39038 | CGS Administrators | Active | A58747 |
L39044 | WPS | Active (orig. 04/17/2022) | A58761 (rev. 10/01/2025) |
The core provisions are unambiguous. Panels cannot be unbundled — a panel is a single test with a single unit of service, regardless of how many pathogens are reported. Under MolDX article A58720, 87798 falls into Group 8 alongside individual analyte codes such as 87486 and 87581. Only two tests for the same intended use are covered per date of service within or across related groups, and Group 1 codes (87631, 87636) cannot be billed with Group 8 codes on the same date for the same intended use.
Expanded panels targeting more than five pathogens in outpatient settings require two ICD-10 codes — one from the panel group and one from the clinical-indication group — and must be ordered by a relevant specialist in infectious disease, pulmonology or gastroenterology. Tests that are not FDA-approved or cleared require Z-code registration through the DEX platform, with approval timelines stretching past 90 days.
No national coverage determination exists for 87798. Contractors outside MolDX — Novitas, First Coast, NGS — follow general Medicare guidance rather than MolDX registration requirements, though MUE limits and NCCI edits still apply. Novitas may accept multiple units of 87798 per encounter, creating jurisdictional inconsistencies that complicate any national billing strategy.
Commercial payers are restricting 87798 from several angles
Cigna's medical coverage policy 0530, effective February 15, 2026, contains perhaps the most explicit commercial restriction: "Use of Not Otherwise Specified (NOS) CPT codes: 87797, 87798, 87799, for molecular microbe testing is not covered or reimbursable when a more specific CPT/HCPCS code is available for use." Cigna also excludes coverage for nail dystrophy, skin and nail fungal infections, urinary-tract infection testing, syphilis, low-risk HPV types and antibiotic-resistance panels.
Aetna (CPB 0650) covers PCR testing for a defined list of organisms but treats 87798 itself with suspicion — requesting medical records on virtually every claim and denying as experimental for UTI, wound and nail-fungal panels. Anthem/Elevance takes an aggressive bundling approach: when two or more individual STI test codes (87491, 87591, 87661) are billed separately, Anthem bundles them into a single unit of 87801, sharply reducing reimbursement regardless of the units billed.
Among Blue Cross Blue Shield plans, the trend is toward outright removal of NOS codes from covered code tables. BCBS Alabama has classified 87797, 87798 and 87799 as investigational and not covered since 2013 and is conducting overpayment reviews with recoupment. BCBS North Carolina removed 87798 from its billing and coding section entirely in August 2023, limiting NOS codes to ten units for vaginitis and STI indications only. BCBS Louisiana similarly removed 87798 from its coverage policy. Blue Shield of California classifies urogenital pathogen panels using 87798 as investigational. BCBS Kansas allows 87798 only for specifically enumerated organisms and returns claims for correct coding when a specific CPT exists.
eviCore, which manages laboratory benefits for several BCBS plans, classifies 87798 as experimental for bacterial vaginosis and STI indications, directing laboratories to specific panel codes — 81513 for Aptima BV, 81514 for the BD MAX vaginal panel — instead. Avalon Healthcare Solutions, the laboratory benefit manager used by BCBS North Carolina, Louisiana and Michigan, adds another layer of claims scrutiny.
UnitedHealthcare covers 87798 conditionally — following Medicare LCD guidance in MolDX jurisdictions and requiring Z-codes for panel-based molecular tests. Its Medicare Advantage plans do not cover multiplex PCR respiratory panels of six or more pathogens. UHC has at times recommended reporting 87798 six times for respiratory organisms in some communications, creating confusion with CMS anti-unbundling rules.
Respiratory and STI panels are the highest-risk scenarios
Two clinical use cases generate most 87798 denials.
For respiratory testing, laboratories face a genuine coding paradox. 87632 (6–11 targets) and 87633 (12–25 targets) are not covered by most Medicare contractors, yet unbundling those panels into individual codes including 87798 violates MolDX anti-unbundling rules and Group 8 limits. The only reliably covered respiratory panel codes are 87631 (3–5 targets) and 87636 and 87637 (the COVID, influenza and RSV combinations). A laboratory running comprehensive respiratory panels of twelve or more targets has no clean billing pathway in MolDX jurisdictions without Z-code registration and technical-assessment approval. Medicare Advantage plans such as Devoted Health deny the individual codes with the message "adjusted when billed as individual tests instead of as a panel," directing laboratories toward panel codes that original Medicare does not cover.
For STI testing, a major coding change arrived on January 1, 2026: CPT 87494, chlamydia trachomatis and neisseria gonorrhoeae by multiplex amplified probe, now replaces the practice of billing 87491 and 87591 together. Quest Diagnostics, ARUP and other major reference laboratories have updated their mappings; laboratories still billing the pair, or using 87798 for those organisms, face immediate denials.
The broader pattern is that the AMA keeps creating organism-specific codes that shrink legitimate 87798 usage — 87640 and 87641 for MRSA, 87500 for vancomycin resistance, 87563 for mycoplasma genitalium — and proprietary laboratory analysis codes are updated quarterly, more than seventy in the past year alone. When a PLA code exists for a proprietary test, it takes precedence over 87798.
Medical-necessity denials cluster around five scenarios
Nearly all managed-care organizations deny large multiplex UTI panels billed as multiple units of 87798, and Medicare contractors are auditing PCR UTI testing with False Claims Act exposure; Centene's Superior HealthPlan states flatly that "current evidence does not support the use of molecular/multiplex UTI panels." Wound-care molecular panels are frequently denied as experimental by Cigna, Aetna and BCBS plans, particularly at ten or more units. Nail and dermatologic fungal testing is excluded outright by Cigna policy 0530 and several BCBS plans. Large respiratory panels in outpatient settings are not covered under MolDX LCDs unless specialist-ordered with dual ICD-10 codes. Routine bacterial vaginosis screening in pregnancy runs into the USPSTF's grade D recommendation against screening low-risk pregnant patients.
ICD-10 codes that consistently fail medical necessity include N39.0 (UTI), L60.x (nail disorders), B37.2 (candidiasis of skin and nail) and pregnancy-complication codes not specifically linked to covered STI screening. Codes that reliably support it include J06.9 (acute upper respiratory infection), J18.9 (pneumonia), Z11.3 (STI screening encounter), A56.xx (chlamydial disease) and N76.0–N76.89 (vaginitis and vulvitis) for symptomatic patients.
Reimbursement is frozen at about $35 — and the freeze ends in January
CPT 87798 is paid under the Clinical Laboratory Fee Schedule, not the physician fee schedule. The rate's trajectory is one of steady erosion: $48.14 in 2017, before PAMA; $43.33 in 2018 after the first 10% cut; about $35 by 2019–2020 after successive annual cuts; and then a rate effectively frozen from 2021 through 2026 by six Congressional interventions, the most recent being Section 6226 of the Consolidated Appropriations Act of 2026, signed February 3, 2026, which eliminated the scheduled phase-in reduction for 2026. Laboratory Economics identified 87798 as one of the tests that would have faced the maximum 15% cut in 2026 absent that fix.
The reprieve is now on its last cycle. The PAMA private-payer data reporting window — covering January through June 2025 — closed on July 31, 2026. CMS publishes its proposed CY2027 determinations in September, held its Clinical Laboratory Fee Schedule public meeting on September 15–16, and issues final determinations in November; the new rates take effect January 1, 2027, with annual reductions capped at 15% a year through 2029. Industry estimates put roughly 800 codes in the exposed set. The RESULTS Act, ACLA's successor to the SALSA bill, has bipartisan backing and more than a hundred cosponsors but had not become law as of August 2026. A laboratory that plans on the freeze continuing is planning on legislation that does not yet exist.
Effective appeals require specific documentation and AMA citation
Laboratories that systematically contest 87798 denials recover substantial revenue, yet most do not contest them at all. The successful strategies share common elements.
The single most impactful change is operational, not clinical: adding the specific test or organism description to the claim narrative before submission. Since 87798 can represent roughly seventy different tests, that one step dramatically reduces medical-records requests and experimental denials by telling the payer exactly what was tested. Humana's front end, for one, rejects an entire claim when an 87798 line lacks a line-level description — a pattern Recovr agents have seen void multi-line pathology claims on the strength of one laboratory line.
For formal appeals, the documentation package should include the laboratory requisition showing what was ordered, the specific test description and panel information, individual organism results demonstrating separately reportable results, clinical-utility literature, LCD-compliant ICD-10 codes and the ordering physician's clinical rationale. Appeals should cite the AMA CPT Professional Edition guidance directly: "The most specific code possible should be reported. If there is no specific agent code, the general methodology code (e.g., 87798) should be used. When separate results are reported for different species or strain of organisms, each result should be coded separately." Laboratories should also reference the MUE limit of 13 units as CMS's own acknowledgment that multiple units are clinically appropriate, and ACLA's 2021 letter to NCCI arguing that the policy manual's "single procedure" language conflicts with AMA guidance. Advance beneficiary notices should be issued proactively whenever the supporting ICD-10 code may not meet LCD requirements or multiple units may trigger an MUE denial.
Strategic adaptation is no longer optional
Three dynamics are converging: expanding payer restrictions on NOS codes, with several BCBS plans removing 87798 from covered tables entirely; CMS enforcement of anti-unbundling through the MolDX LCDs, limiting Group 8 to two tests per date of service for the same intended use; and the resumption of PAMA cuts in January 2027.
Five actions follow. Pursue PLA code registration for proprietary tests to escape NOS-code vulnerability. Ensure Z-code registration through DEX for all molecular panels, since UHC now requires Z-codes nationally across commercial, Medicare Advantage and Medicaid plans, not only in MolDX jurisdictions. Build payer-specific compliance matrices mapping coverage criteria, diagnosis-code requirements and modifier rules by plan, because the gap between BCBS Alabama's total non-coverage and Novitas's acceptance of multiple units is vast. Put the organism description on the line before the claim leaves the building. And transition to 87494 for chlamydia and gonorrhoea combination testing while monitoring quarterly PLA updates for any new code that supersedes 87798.
The fundamental tension — the AMA supports unbundled per-organism billing while CMS enforces single-code panel billing — remains unresolved and may never be reconciled. Laboratories that build their revenue cycle around that reality, rather than waiting for policy harmonization, are the ones that will sustain molecular programs through the turbulence ahead.
Sources include the XiFin 2024 Payor Denial Impact Report; MolDX LCDs L38988, L39001, L39003, L39038 and L39044 and billing articles A58710, A58720, A58726, A58747 and A58761; Cigna medical coverage policy 0530 (effective February 15, 2026); Aetna clinical policy bulletin 0650; published BCBS, eviCore and Avalon laboratory policies; the Consolidated Appropriations Act of 2026, Section 6226, and CMS change request 14312; CMS Clinical Laboratory Fee Schedule public-meeting materials for CY2027; ACLA materials on the RESULTS Act; and the AMA CPT Professional Edition. Policy details were verified as of March 2026 and should be re-checked against current payer bulletins before use in an appeal.
