96521 is refilling and maintenance of a portable pump — the take-home device a patient carries out of the infusion suite, most often a 46-hour 5-FU pump.
96522 is refilling and maintenance of an implantable pump or reservoir for systemic drug delivery — a device under the skin, not one the patient carries.
96523 is irrigation — a flush — of an implanted venous access device. Medicare pays it only when it is the only service billed that day. Any visit, injection, or infusion on the same date absorbs it.
| Code | Descriptor | The device |
|---|---|---|
| 96521 | Refilling and maintenance of portable pump | External and portable. The patient leaves with it. Elastomeric or electronic ambulatory pumps used for continuous infusion. |
| 96522 | Refilling and maintenance of implantable pump or reservoir for drug delivery, systemic | Implanted. Surgically placed under the skin. Refilled by percutaneous access, not carried. |
| 96523 | Irrigation of implanted venous access device for drug delivery systems | A port, not a pump. This is the flush that keeps an implanted venous access device patent. |
None of the three is an add-on. Each stands on its own, which is exactly why the bundling rules below matter so much: nothing about the code structure stops you from putting one on a claim where it does not belong.
| Code | Non-facility | Facility | Total RVU |
|---|---|---|---|
| 96521 — portable pump refill | $143.62 | $143.62 | 4.30 |
| 96522 — implantable pump or reservoir refill | $125.25 | $125.25 | 3.75 |
| 96523 — implanted venous access device irrigation | $26.05 | $26.05 | 0.78 |
The spread is the thing to notice. A pump refill pays roughly five and a half times what a port flush pays, and the flush is the one that is usually bundled. Practices lose money in this family by billing the $26 code they cannot keep, and by missing the $143 code they could.
96523 is payable only when it is the only service that day. If the patient also had an office visit, an injection, or any infusion on the same date, Medicare treats the flush as included in that service and pays nothing extra for it. A port flush on its own day is a billable encounter; a port flush attached to anything else is not.
The distinction is the device, not the drug and not the duration. Ask one question: did the patient leave with the pump on them?
This one is genuinely contested, and it is worth stating honestly rather than picking a side and sounding certain.
The descriptor for 96521 reads refilling and maintenance of a portable pump. A patient returning on day three of a FOLFOX cycle to have the 46-hour pump taken off is not being refilled, and whether that visit is "maintenance" is where practices and payers disagree. AMA CPT Assistant has published specific guidance on reporting 96521 (June 2026) but it sits behind the AMA's paywall, so this page does not claim to settle it.
What is not in dispute: a refill visit is 96521. A visit where the pump is only disconnected and nothing else happens is commonly reported as a low-level established-patient visit instead, and a number of payers expect exactly that. If your practice bills 96521 for disconnect-only encounters, confirm it against your MAC's guidance and keep the documentation that supports it — this is a line item that gets looked at.
Medicare (all MACs). 96523 is payable only as the sole service of the day; otherwise it is included in the other service's payment. NCCI edits pair 96521 and 96522 against 96416. Professional charges in this family are for the office setting.
Commercial payers. Most mirror the Medicare bundling logic, but the sole-service rule for 96523 is applied with varying strictness, and some plans reimburse a disconnect-only encounter differently from Medicare. Where a payer's policy is silent, the safest reading is the Medicare one.
All payers. The documentation that carries these claims is device-specific: which device, what was done to it, and what else happened at the encounter. "Port flushed" on a day with an infusion is a denial waiting to be written.
| What comes back | Why | The fix |
|---|---|---|
| Flush bundled into another service | 96523 reported on a date that also carried a visit, injection or infusion | Remove the 96523 line. It is not appealable — the rule is that the flush is included, not that it was under-documented. |
| Unbundling / NCCI edit against 96416 | 96521 or 96522 submitted alongside prolonged-infusion initiation | Drop the refill line for that encounter. Report 96521 at the visit where the pump is actually refilled. |
| Place-of-service denial | Professional charge submitted for a service rendered in a hospital or the patient's home | These codes carry a professional charge in the office setting. Re-route the billing to the correct party for the setting. |
| Wrong device code | 96522 billed for a take-home pump, or 96521 for an implanted reservoir | Rebill against the device. Portable and worn out of the suite is 96521; implanted under the skin is 96522. |
| Refill code on a disconnect-only visit | 96521 reported for an encounter where the pump was removed and nothing refilled | Check your payer's position before appealing. Many expect a low-level established-patient visit for a disconnect-only encounter. |
Only when it is the sole service billed for that date. Medicare includes the flush in payment for any visit, injection, or infusion performed the same day. A standalone maintenance flush between cycles, documented as its own encounter in the office setting, is the case that pays.
No. Accessing and flushing an implanted device in order to deliver an infusion is inherent to that infusion and is not separately reportable. It is both a same-day bundling problem and an unbundling problem, and it is the most frequent misuse of the code.
The device, not the drug. 96521 is a portable pump — external, carried or worn by the patient, such as the 46-hour 5-FU pump. 96522 is an implantable pump or reservoir placed under the skin and refilled by percutaneous access. If the patient walked out wearing it, it is 96521.
No. 96521 and 96522 are not reported with 96416, the initiation of a prolonged chemotherapy infusion using a pump. Initiation already contemplates setting the pump up; the refill code applies at a later encounter when the pump is genuinely refilled.
Contested. The descriptor says refilling and maintenance, and practices differ on whether a disconnect-only encounter qualifies. AMA CPT Assistant addressed 96521 in June 2026 but the guidance is paywalled, so this page does not claim to settle it. What is safe: a genuine refill is 96521, and many payers expect a low-level established-patient visit for a disconnect-only encounter. Confirm against your MAC and keep the documentation.
Professional charges for 96521 through 96523 are intended for the physician-office setting. They should not be submitted for services administered in a hospital or in the patient's home, where the billing party and mechanism differ.
$26.05 nationally for CY2026, against $143.62 for a portable pump refill. The economics are worth understanding before you build a workflow around the flush: it is a low-value code that is bundled in most of the circumstances where staff actually perform the task.
Not by itself. If it is genuinely the only service of the day, it stands alone and no modifier is required. Reaching for a modifier to force payment alongside another same-day service is the wrong move — the bundling is by policy, not by edit-override.