What every code on your bill actually means
Hospital and doctor bills are full of cryptic CPT and HCPCS codes. Find 612 of the most commonly billed codes below, organized by category. For each one we explain what the service is, the Medicare fair-price anchor, and the audit issues we look for when patients send us the bill.
- Office & evaluation visits84 codes
Doctor visits, established patient checkups, and consultations. The most commonly billed codes on outpatient bills, and the ones most often upcoded.
- Emergency department visits5 codes
ER visit level codes (99281–99285) plus common facility fees. ER visit level upcoding is one of the most common billing errors we see.
- Lab panels & blood tests114 codes
Routine blood draws and panels — comprehensive metabolic panel, CBC, lipid panel, A1c, urinalysis. Frequently unbundled or duplicated on hospital bills.
- Imaging (X-ray, CT, MRI, ultrasound)125 codes
Radiology codes. Both the technical (facility) and professional (radiologist) components can show up on separate bills — make sure you're not being charged twice.
- Preventive care & vaccines68 codes
Annual physicals, well-woman visits, vaccine administration. Most preventive services are required to be covered at $0 by ACA-compliant insurance — so any patient balance for these is worth disputing.
- Minor procedures & surgery158 codes
Common outpatient procedures — biopsies, joint injections, sutures, colonoscopies. Frequently bundled in ways that cause double-billing.
- Supplies, equipment & drugs (HCPCS)58 codes
HCPCS Level II codes for durable medical equipment, drugs, and supplies. Lots of room for billing for items the patient never received.