Key Takeaways Urology denials cluster around specific procedures, not one universal coding mistake. CPT 55700 was deleted for 2026 and replaced by a nine-code family that bundles imaging into the biopsy code itself. NCCI edits bundle diagnostic cystoscopy into nearly every therapeutic cystoscopy code performed in the same session. Missing laterality modifiers on lithotripsy and […]
Carola Cornejo
Assistant Vice President of Client Services and Operations
Carola Cornejo is Assistant Vice President of Client Services and Operations at PGM Billing, where she has spent more than 15 years specializing in physician billing and revenue cycle management. She is one of PGM’s leading experts in appeals filing and denial resolution, with hands-on experience across patient and insurance collections, claims follow-up, fee schedule analysis, and provider credentialing.
Carola’s work spans PGM’s core physician specialties — including cardiology, orthopedics, neurology, gastroenterology, behavioral health, nephrology, and oncology — making her a trusted resource for practices navigating complex billing and coding challenges. She holds a degree in Computerized Accounting from Dover Business College.
Posts by Carola Cornejo
The Coding and Billing Mistakes Behind Denied Allergy and Immunotherapy Claims
Key takeaways Allergy testing and immunotherapy use separate, non-interchangeable CPT code sets. Billing the wrong code combination triggers denials regardless of medical necessity. Immunotherapy dose miscounting is one of the most common sources of underpayment. Medicare does not cover complete-service immunotherapy codes; component billing is required. Modifier 25 has specific, narrow rules for same-day E/M […]
Neurology Billing Collections: Where Practices Lose Revenue and How to Recover It
Key takeaways Neurology billing volume does not guarantee strong collections. Time-based E/M documentation gaps delay or reduce reimbursement. Prior authorization requirements for EMG, nerve conduction studies, and imaging create cash flow lags. Botox and infusion billing errors are a common source of lost revenue. Days in A/R and denial patterns reveal where collections break down. […]
Nephrology Billing Errors: ESRD Monthly Capitation Payment Rules Practices Get Wrong
Key Takeaways The ESRD Monthly Capitation Payment (MCP) is a single monthly code, not a per-visit fee, and code selection depends on the patient’s age and the number of face-to-face visits completed that month. Only one MCP claim is allowed per patient per month, and the billing physician must personally provide at least one of […]
Chemotherapy and Infusion Billing: Coding Errors That Cost Oncology Practices
Key Takeaways Chemotherapy administration must be sequenced before therapeutic infusions and hydration on every multi-service claim. Start and stop times are required for time-based infusion codes — missing documentation forfeits add-on code reimbursement. The JW and JZ modifiers are mandatory on Medicare claims for single-dose vial drugs; missing either causes claims to be returned unprocessable. […]
Orthopedic Billing Denials: Why Claims Fail by Procedure Type
Key Takeaways Joint replacement denials are most often documentation failures, not coding errors — prior authorization and conservative treatment records have to be in the chart before the claim goes out. Fracture care claims fail at the ICD-10 level more than any other orthopedic category; episode-of-care suffix errors and missing laterality are consistent, avoidable denial […]
Medicare Billing for Chiropractors: Coverage Rules, Exclusions, and the Mistakes That Lead to Denials
Key Takeaways Medicare covers exactly one chiropractic service: manual spinal manipulation to correct a subluxation. Every other service a chiropractor commonly provides — x-rays, E/M visits, massage, e-stim, ultrasound, extraspinal manipulation — is statutorily excluded. The AT modifier is required on every Medicare claim for spinal manipulation. Without it, the MAC denies the claim automatically, […]
Why Nephrology Billing Is Harder to Manage In-House Than Most Practices Expect
Key Takeaways Nephrology practices carry some of the most documentation-intensive billing requirements in outpatient medicine, driven by CKD staging specificity, high-comorbidity E/M coding, and long-term patient management patterns. ICD-10 staging codes for chronic kidney disease directly affect medical necessity determinations — incomplete or unspecified staging is one of the most consistent sources of preventable denials […]