CPT Code Overview

CPT 87040 describes a definitive bacterial culture from any source except urine, blood, or stool, reported per organism and including antimicrobial susceptibility testing when performed. This code applies to pathology and laboratory services and is used for identifying causative bacterial organisms from clinical specimens other than the excluded specimen types. Typical sites of service for CPT 87040 are laboratory settings, most commonly ambulatory or hospital outpatient laboratories (likely place of service 19 or 23).

Clinical Context

A patient presents to an urgent care clinic or emergency department with fever, rigors, and hypotension. Bloodwork is obtained and the clinician orders laboratory testing to identify a possible bacterial source from a non-sterile site (for example, wound or respiratory tract) when urine, blood, and stool cultures are not indicated. A specimen (such as a wound swab, sputum, or respiratory secretions) is collected by nursing or respiratory therapy and sent to the laboratory. In the microbiology laboratory, a technologist performs a definitive bacterial culture from the submitted non-urine, non-blood, non-stool source. If an organism is isolated, identification and antimicrobial susceptibility testing are performed as part of the same workup when indicated. Results are reported to the ordering clinician to guide antimicrobial therapy and further clinical management.

Coding Specifications

• Modifier 26 (Professional Component): Used when reporting only the professional interpretation or reading component of the laboratory service performed by a qualified pathologist or laboratory physician. Apply when the laboratory technical component is billed separately by the performing facility.

• Modifier 90 (Reference (Outside) Laboratory): Used when the testing is performed by an outside or reference laboratory and the ordering facility bills for the service. Apply when the specimen is sent out to a third-party laboratory for definitive culture and susceptibility.

• Associated provider taxonomies and specialties:

Related Diagnoses

• R50.9 — Fever, unspecified

  Fever is a common clinical presentation prompting specimen collection and bacterial culture from non-urine, non-blood, non-stool sources to seek a focal infectious etiology.

• A41.9 — Sepsis, unspecified organism

  Sepsis may prompt directed cultures from potential infectious sites; culturing non-sterile sources can identify causative organisms contributing to systemic infection.

• R78.81 — Bacteremia

  Although bacteremia is a blood-stream diagnosis, cultures from other sources may be obtained to identify the primary source of bacteremia and guide targeted therapy.

• R65.21 — Severe sepsis with septic shock

  In severe sepsis or septic shock, rapid and definitive microbiology (including cultures and susceptibility) from relevant sources is clinically important for organism identification and antimicrobial selection.

• R65.20 — Severe sepsis without septic shock

  Severe sepsis without shock similarly warrants comprehensive culture workup from suspected infectious sites to identify pathogens and direct treatment.

Related CPT Codes

• 87070 relates as a culture procedure that includes isolation and presumptive identification; it is commonly used when isolation with preliminary ID is specifically reported and may be billed in workflows where additional isolation steps are documented.

• 87186 relates as a specific susceptibility testing methodology (MIC or breakpoint) and is used when detailed quantitative antimicrobial susceptibility panels are required; it may be billed in conjunction with culture workup when susceptibility testing is performed beyond routine methods.

• 87205 relates as a primary smear with microscopic interpretation (e.g., Gram stain) often performed on the same specimen prior to or concurrent with culture to provide rapid preliminary information; it is commonly performed together with culture services.

• 87880 relates as an immunoassay-based antigen detection for a specific organism (group A Streptococcus) and may be an alternative rapid diagnostic test performed on certain specimens instead of or prior to culture depending on clinical need.

• Common combinations and alternatives: 87205 (smear) is commonly performed together with the culture service represented by 87040; 87186 (susceptibility) may be reported when quantitative susceptibility testing is performed in addition to culture. 87070 may be used when the reporting emphasizes isolation and presumptive identification steps rather than definitive culture reporting. 87880 is an alternative rapid test for specific pathogens and can precede culture.

National commercial mean rates for 87040 cluster above Medicare when using BUCA as the composite commercial benchmark: BUCA (average commercial) mean is $11.03 while Medicare is represented as not available in the input and is therefore shown as $0.00 in the table and chart. Aetna and Cigna report the highest commercial means at $13.15 and $13.76 respectively, with Blue Cross Blue Shield and UnitedHealth Group lower at $10.26 and $8.76.

Dispersion measured by the interquartile range (P75 − P25) varies across payers. Cigna shows the widest spread (approximately 8.33), driven by a high P75 of 14.33 and a P25 of 6.00. UnitedHealth Group and Aetna show tighter distributions (ranges of 5.50 and 5.50 respectively). The table and chart below present the full breakdown of mean rates and percentiles for each payer.