Procalcitonin (PCT) — CPB 0771 | AETNA Coverage Update

Aetna modified CPB 0771 covering procalcitonin (PCT) testing under CPT 84145, effective November 15, 2025. Here's what billing teams need to know.

Aetna, a CVS Health company, updated its procalcitonin coverage policy under CPB 0771. The policy draws a sharp line between two covered indications and a long list of experimental or non-covered uses. If your facility bills CPT 84145 for PCT testing in any setting outside the ICU or inpatient respiratory tract infections — or for febrile infant risk stratification — your claims are at risk.

Aetna Procalcitonin Coverage Criteria and Medical Necessity Requirements 2025

Aetna's procalcitonin coverage policy under CPB 0771 covers CPT 84145 for only two clinical scenarios. Both have specific patient and setting criteria. Neither is a gray area.

Indication 1: Febrile infants aged 8 to 60 days. Aetna considers PCT measurement medically necessary to help risk-stratify well-appearing febrile infants in this age range for invasive bacterial infection. The patient must be well-appearing. Age outside the 8-to-60-day window disqualifies the claim. "Evaluation of fever of uncertain source in infants" is explicitly listed as experimental — so the covered indication is narrow. Document the patient's age and clinical appearance clearly in the record.

Indication 2: Antibiotic therapy guidance in ICU and inpatient settings. Aetna covers PCT measurement to initiate or discontinue antibiotic therapy for two groups: persons in the ICU, and persons with respiratory tract infections in the inpatient hospital setting. The stated purpose is reducing antibiotic prescription rates and duration of use. This does not extend to the emergency department, ambulatory care, or community settings. Those are explicitly excluded.

Medical necessity for CPT 84145 reimbursement hinges on documenting both the clinical setting (ICU or inpatient) and the purpose (antibiotic stewardship). If your documentation says "rule out sepsis" on an ED patient, that's a claim denial waiting to happen. Prior authorization requirements are not specifically called out in CPB 0771, but given how many uses are listed as experimental, verify prior auth status with Aetna directly before billing for edge cases.

Aetna Procalcitonin Exclusions and Non-Covered Indications

This is where CPB 0771 gets extensive — and where most billing exposure lives. Aetna lists more than 40 indications as experimental, investigational, or unproven. Here are the ones most likely to affect your teams in practice.

Surgical and post-operative settings. PCT use for diagnosing surgical infections — including cervical cerclage (CPT 59320, 59325), intra-abdominal infection after elective colorectal surgery, and peri-prosthetic joint infection — is not covered. PCT after pancreatoduodenectomy (CPT 48150–48154) for post-operative pancreatic fistula is also experimental. If your surgical teams order PCT routinely post-op, those claims will not pay.

Emergency and ambulatory care. Evaluation of suspected lower respiratory tract infection or sepsis in the ED or outpatient setting is experimental. So is differential diagnosis between bacterial and viral pneumonia in the community setting. This matters because PCT use in the ED has become routine at many hospitals. Aetna will not cover it under this policy.

Specific infections and conditions. Aetna does not consider PCT medically necessary for diagnosing bacterial meningitis, infective endocarditis, urinary tract infections, acute pyelonephritis, ventilator-associated pneumonia, appendicitis, or spontaneous bacterial peritonitis. Sepsis after cardiac surgery (CPT codes 33016–33997) is also excluded.

Other notable exclusions. COVID-19 severity and prognosis, medullary thyroid carcinoma (ICD-10 C73), febrile neutropenia, ARDS prediction, septic shock mortality prediction, and immunocompromised patient management are all experimental under this policy. If your oncology or critical care teams use PCT for any of these, review those order sets now.

The real issue here is volume. PCT is a single CPT code — 84145 — but it gets ordered for dozens of different reasons. One code, many clinical contexts, and only two of those contexts pass Aetna's medical necessity threshold. That's a high denial risk for facilities where ordering culture has outpaced coverage policy.

Coverage Indications at a Glance

Aetna Procalcitonin Billing Guidelines and Action Items 2025

The effective date is November 15, 2025. Here's what your billing team needs to do before then.

CPT, HCPCS, and ICD-10 Codes for Procalcitonin Testing Under CPB 0771

Covered CPT Codes (When Selection Criteria Are Met)

Other CPT Codes Referenced in CPB 0771

These codes appear in the policy as related procedures. PCT ordered in connection with these procedures is generally not covered under CPB 0771.

Key ICD-10-CM Diagnosis Codes

These codes appear in CPB 0771. Most map to experimental or non-covered indications. Use them only with covered indications where documentation supports medical necessity.

CPB 0771 includes 473 ICD-10-CM codes in total. The codes above represent the most commonly billed categories. Review the full code list at app.payerpolicy.org/p/aetna/0771 before finalizing your documentation mapping.