What Is the CPT Code for a Strep Test?

Accurate medical coding is vital for clinics, laboratories, and physician offices. When a strep test is performed to diagnose streptococcal pharyngitis (commonly known as strep throat), choosing the correct CPT code ensures proper reimbursement and compliance. Let’s explore the CPT codes used for strep testing, common pitfalls, and billing best practices.

Types of Strep Tests

There are two common diagnostic approaches:

1. Rapid Antigen Detection Test (RADT / “Rapid Strep Test”)
   This test detects streptococcal antigens from a throat swab and provides results within minutes.
   • Common CPT: 87880 (Infectious agent antigen detection by immunoassay; Streptococcus, group A, direct optical observation).
2. Throat Culture
   If the rapid test is negative, a throat culture may be ordered for confirmation.
   • Common CPT: 87081 (Culture, presumptive, pathogenic organisms, screening only).
3. Molecular (NAAT) Tests
   Some labs use nucleic acid amplification tests for Group A strep.
   • Common CPT: 87651 (Infectious agent detection by nucleic acid, Streptococcus, group A).

Standard CPT Codes for Strep Tests

Choosing the right code depends on which method is used, not just the diagnosis.

Reflex Testing (Rapid + Culture)

Many practices use a reflex testing protocol:

• A rapid test (87880) is performed first.
• If negative, the sample is sent for culture (87081).
• Both may be billed, provided documentation supports that both tests were conducted.

This setup ensures accuracy while minimizing unnecessary cultures.

Common Coding Pitfalls

• Incorrect CPT selection: Using 87449 (infectious agent antigen detection, multiple organisms) instead of 87880.
• Overlooking modifiers or edits: Be aware of Correct Coding Initiative (CCI) edits when combining codes like 87880 and 87651.
• Insufficient documentation: Always specify whether the test was antigen, molecular, or culture-based.

Working with experts in medical billing and coding helps reduce these errors and supports smoother claim approvals.

Why Proper Coding Matters

For providers and labs, using the correct CPT code ensures:

• Claims are paid without denial.
• Compliance with payer rules.
• Accurate reporting for preventive and diagnostic services.

For example, when billing a CPT code for rapid strep test, the accuracy directly impacts whether reimbursement is timely and complete.

At EZ Settle Solutions, our services are designed to support providers in achieving compliance, efficiency, and peace of mind in the billing process.

For additional coding guidance, refer to AAPC’s coding article on rapid strep test CPT code 87880.

Final Thoughts

The CPT code for a strep test depends on whether the test is a rapid antigen (87880), molecular assay (87651), or culture (87081). Correct selection helps avoid claim denials, ensures compliance, and improves revenue cycle efficiency. By staying current with coding updates and partnering with billing experts, providers can focus on delivering patient care while maintaining smooth financial operations.