Modifier 63 is used to indicate that a procedure was performed on an infant weighing less than 4 kilograms (approximately 8.8 pounds). Infants require specialized techniques, anesthesia, and equipment due to their size and physiology. Modifier 63 indicates increased complexity and typically results in higher reimbursement (usually 50% increase over standard pediatric code).
Document infant's weight in grams or kilograms in operative report. Confirm weight is under 4kg. Document specialized techniques or challenges due to infant size. Note anesthesia considerations for neonate. Indicate any complications or extended operative time due to infant physiology. Discharge summary or hospital records should confirm infant status at time of procedure.
| Payer | Acceptance | Common Denials | Notes |
|---|---|---|---|
| Medicare | Accepted; 50% increase for infant codes | CO-16: Service not medically necessary | Allow 63. Reimburse at increased rate for infant procedures. Require weight documentation. |
| Aetna | Accepted; modifier 63 increase | CO-151: Documentation missing | Will pay increased amount for 63. Require infant weight. |
| United Healthcare | Accepted; infant procedure increase | CO-20: Charge exceeds fee schedule | Pay 63 increase. Require verification infant under 4kg. |
| Cigna | Accepted with weight documentation | CO-63: Infant weight not documented | Will pay increased rate. Require weight confirmation. |
| Humana | Accepted; standard infant increase | CO-16: Service not medically necessary | Routine approval. Pay increased infant procedure rate. |
| CARC Code | Reason | Primary Cause |
|---|---|---|
| CO-16 | Service not medically necessary | Payer deems specialized infant procedure not necessary or not covered. |
| CO-151 | Documentation missing | Claim lacks infant weight documentation. |
| CO-63 | Infant weight not documented | Claim does not provide evidence infant was under 4kg. |
Less than 4 kilograms (8.8 pounds). Infants at or above 4kg do not qualify for 63.
Medicare typically pays approximately 50% more for infant procedures than standard pediatric codes.
No. Modifier 63 is specifically for infants under 4kg. Do not use if infant weighs 4kg or more.
Ensure infant procedure reimbursement. Use a co-pilot to verify weight documentation.