Summary & Overview
CPT 0224U: Mount Sinai COVID-19 IgG Antibody Test
CPT code 0224U identifies a Proprietary Laboratory Analyses (PLA) assay for the Mount Sinai COVID‑19 Antibody Test, a serologic test targeting human IgG to SARS–CoV–2. As a PLA code, 0224U applies to a single manufacturer-specific test and is used in claims to distinguish this unique laboratory service. Nationally, PLA codes like 0224U matter because they enable tracking and reimbursement of proprietary assays developed during public health responses and for specialized diagnostics.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the clinical context for SARS–CoV–2 IgG antibody testing, typical sites of service and laboratory workflows, and the billing implications of a PLA-level CPT code. The publication summarizes payer coverage patterns and benchmarks where available, explains coding and claim reporting conventions for proprietary tests, and highlights policy considerations tied to PLA coding and laboratory-developed testing. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 0224U is a Proprietary Laboratory Analyses (PLA) code for the Mount Sinai COVID-19 Antibody Test, a laboratory assay that detects human IgG antibodies to SARS–CoV–2 in serum and plasma specimens. The test may include antibody titers to measure the concentration of IgG antibodies in blood.
Service type: Laboratory — serology/antibody testing
Typical site of service: Clinical laboratory or hospital laboratory (specimen collection may occur in outpatient clinics or phlebotomy sites)
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult or pediatric outpatient who presents to a primary care clinic, occupational health clinic, blood draw station, or hospital outpatient phlebotomy service seeking evaluation of prior exposure to SARS–CoV–2. The clinician documents symptoms consistent with past COVID-19 illness or documents a history of a positive viral test and requests serologic confirmation of IgG antibody response. A venous blood specimen (serum or plasma) is collected by trained phlebotomy staff and sent to the laboratory performing the proprietary Mount Sinai COVID–19 Antibody Test. The laboratory analyst performs the assay, which may include reporting qualitative IgG detection and, when ordered, antibody titers reflecting concentration. Results are returned to the ordering provider and incorporated into the patient’s electronic health record; results may inform occupational clearance, seroprevalence assessment, post-infection immune response evaluation, or eligibility for certain studies. Typical sites of service include outpatient clinics, hospital outpatient labs, commercial reference laboratories, and dedicated phlebotomy centers. The service type is clinical laboratory testing (Proprietary Laboratory Analyses, PLA) performed by a certified clinical laboratory using a manufacturer-specific assay.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | Default/No modifier | Used when no other modifier applies to the claim. |
26 | Professional component | Use when billing only the professional interpretation portion, if applicable for consultative test interpretation. |
TC | Technical component | Use when billing only the technical component (laboratory testing) and another entity bills the professional component. |
QW | CLIA waived test | Use if the specific assay is performed at a CLIA-waived site and the PLA meet waiver criteria (rare for PLA codes). |
QX | Ordering clinician CLIA waived certificate | Use when the ordering practitioner is CLIA-waived and performing the test under that certificate. |
QY | Laboratory certified under CLIA for moderate complexity | Use when the testing lab is certified to perform moderate-complexity testing and the test is billed accordingly. |
SH | Items and services furnished under a clinical research study, not for immediate clinical use | Use when the test is performed under an approved clinical trial and the cost is billed separately. |
SJ | Investigational device exemption (IDE) | Use when testing is performed under an IDE and must be identified on the claim. |
52 | Reduced services | Use when the test is partially performed or specimen insufficient and a reduced-service report is appropriate. |
53 | Discontinued procedure | Use if specimen collection or testing was started but discontinued for reasons unrelated to patient condition. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 207Q00000X | Infectious Disease | Physicians who evaluate patients for prior SARS–CoV–2 infection and order serology. |
| 208D00000X | Pathology | Pathologists responsible for laboratory oversight, test validation, and result interpretation. |
| 363L00000X | Clinical Laboratory | Clinical laboratory technicians and directors who perform and report the PLA assay. |
| 207L00000X | Internal Medicine | Primary care and internal medicine clinicians who order serology for patient management. |
| 207P00000X | Emergency Medicine | Emergency clinicians who may order serology in select post-acute evaluations. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
Z86.16 | Personal history of COVID-19 | Indicates prior SARS–CoV–2 infection; serology may document post-infectious antibody presence. |
Z20.828 | Contact with and (suspected) exposure to other viral communicable diseases | Used when assessing possible prior exposure and ordering serologic testing. |
R68.89 | Other general symptoms and signs | Nonspecific post-infectious symptoms prompting evaluation with antibody testing. |
R53.83 | Other fatigue | Post-viral fatigue evaluation where serology may support prior infection as a potential cause. |
Z00.6 | Encounter for examination for normal comparison and control in clinical research program | Used when serology is performed as part of research or surveillance efforts assessing seroprevalence. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
81002 | Urinalysis, by dipstick or tablet reagent; automated, without microscopy | Common point-of-care test performed at the same visit for general screening; unrelated to antibody measurement but often billed from outpatient encounters. |
36415 | Collection of venous blood by venipuncture | Performed immediately prior to sending serum or plasma to the laboratory for the 0224U assay; documents specimen collection. |
99000 | Handling and/or conveyance of specimen for transfer from physician office to a laboratory | Used when clinical offices bill for specimen handling/shipping to the reference lab performing the proprietary assay. |
99070 | Supplies and materials (e.g., local and systemic medications), used in the office (list drugs, trays, supplies) | May be billed by the ordering facility for specific supplies related to phlebotomy when separately billable. |
87635 | Infectious agent antigen detection by immunoassay, (e.g., SARS-CoV-2) | Often performed earlier in the clinical course for acute infection; serology 0224U is complementary for prior exposure assessment. |