Who gets paid for the 90 days after cataract surgery when the surgeon operates but an optometrist handles the follow-up? In cataract co-management billing, both do, as long as each bills only its share of the global package. The surgeon reports the cataract code with modifier 54, the co-managing provider reports the same code with modifier 55, and Medicare splits one fee between them.
The split only works when both claims match: same CPT code, same surgery date, same eye and post-op days that add up. When they don’t, one claim rejects or both pay out wrong. The sections below cover each office’s claim, the paperwork behind it and the compliance lines co-management cannot cross.
How the 90-Day Global Splits
The 66984 global period, like that of 66982, runs 90 days, and cataract cases are where ophthalmology uses split global surgery most. The fee covers three parts: the pre-op visit, the surgery itself and routine post-op care for 90 days.
For 66984, the Medicare fee schedule divides the global roughly 10% pre-op, 70% intra-op and 20% post-op, as shown in the First Coast co-management guide. The surgeon billing modifier 54 receives the pre-op and intra-op share, about 80%. The co-managing provider billing modifier 55 receives the post-op share, about 20%, prorated by the days of care actually provided.
So a co-manager who takes over on day 1 and provides 89 days of care earns payment for 89 of the 90 days. A late transfer, or care that returns to the surgeon, shrinks that share.
In short, surgeons and optometrists split the global in five steps:
- Agree in writing before surgery, with the patient’s signed consent.
- Surgeon bills 66984-54 with the eye modifier, for the pre-op and surgery share of about 80%.
- Surgeon notes the transfer date, so the claim shows where their care ended.
- Optometrist bills 66984-55 after the first post-op visit, using the surgery date and the post-op date span.
- Medicare prorates the 55 share, so 89 days of care pays about 19.8% of the global (89/90 of 20%).
Both claims must use the same code, date of service and eye. The sections below show how to build each one.
Modifier 54 vs 55: Surgeon and Co-Manager Claims
Medicare edits compare the two claims line by line. The Noridian modifier 55 guidance and First Coast both require the same procedure code and the same date of service on each.
| Claim field | Surgeon | Co-managing provider |
|---|---|---|
| Procedure code | 66984 or 66982 | Same code as the surgeon |
| Modifiers | 54 plus RT or LT | 55 plus RT or LT |
| Date of service | Surgery date | Surgery date, not the first post-op visit |
| Units | 1 | 1 |
| Item 19 or electronic note | Date care was transferred | Post-op dates assumed and number of days |
| When to bill | After surgery | After the first post-op visit |
In cataract co-management billing for Medicare, post-op days and units go in separate fields: units stay at 1, and the post-op days go in item 19 or the electronic note. Some commercial plans ask for days in the units field instead, so check each payer’s rule.
The Surgeon’s Claim
The surgeon bills 66984-54-RT, for example, and notes the transfer date. If the surgeon also sees the patient for part of the post-op period, such as the day-1 check, a second line goes on the same claim with modifier 55 and those dates.
The AAO compliance guidance gives this example: a transfer on day 7 of 66982 on the left eye. The surgeon bills 66982-54-LT and 66982-55-LT with a 7-day span, and the co-manager bills 66982-55-LT with the remaining 83 days.
The Co-Managing Provider’s Claim
For optometrist post-op care, or an ophthalmologist taking over, the co-manager cannot bill until after the first post-op visit. The claim then carries the surgery date, modifier 55 and the post-op date span in item 19. However, the co-manager does not bill routine post-op visits inside that span separately with eye visit or E/M codes.
No Formal Transfer? G0559, Not 55
Since 2025, Medicare requires modifier 54 even for informal transfers, such as a patient who never returns to the surgeon. A clinician outside the surgeon’s group who sees that patient post-op, with no written transfer, may bill add-on G0559 once per global period instead of modifier 55, as Retina Today explains. Under a written co-management agreement, modifier 55 still applies.
Cataract Co-Management Billing Documentation
Medicare requires a written, dated co-management agreement documenting the transfer of care, with a copy in each office’s record. Without it, the modifier 55 claim has nothing to stand on in an audit. A clean file holds:
- Patient consent: signed before surgery, after the patient hears the reasons, risks and benefits of co-management
- Transfer agreement: signed by both providers, naming the eye, the procedure and the exact transfer date
- Acceptance of care: the co-managing provider’s written agreement to take over
- Clinical handoff: operative note and post-op instructions sent with the transfer
- Visit notes: each post-op visit documented, so the chart supports every day billed
A typical 90-day timeline looks like this:
- Pre-op: the surgeon examines the patient, documents medical necessity and records the patient’s choice to co-manage.
- Day 0: surgery. The surgeon bills 66984-54 with the transfer date.
- Day 1: the post-op check, by the surgeon or the co-manager, as the agreement states.
- Days 1 to 90: the co-manager provides routine post-op care, then bills 66984-55 after the first visit.
- Complication: if care returns to the surgeon, both offices correct their date spans.
Post-op days on the claim must match the chart. Billing more days than documented is one of the first things an auditor checks.
The Cases That Break Clean Splits
Most cataract co-management billing denials come from situations the standard template does not cover.
Second-Eye Surgery
Each eye has its own 90-day global. When the surgeon operates on the second eye during the first eye’s global, the surgeon adds modifier 79, for example 66984-54-79-LT. The co-manager then files a separate 55 claim for the second eye, with its own surgery date and date span.
The two post-op periods overlap, and that is expected. RT and LT keep the claims apart, and each date span tracks its own eye. Our guide to cataract and glaucoma coding covers modifier 79 and the other cataract modifiers.
Combined Procedures
When the surgeon combines cataract surgery with a second procedure, such as a MIGS device, co-management is all or nothing. The surgeon cannot keep post-op care for one procedure and transfer the other.
Payers That Don’t Recognize Co-Management
Some commercial and Medicare Advantage plans do not accept modifiers 54 and 55. For those patients, the AAO guidance is clear: the surgeon provides all post-op care, and the co-managing office does not bill. Checking each plan’s policy before scheduling avoids a claim no payer will ever pay.
Co-management also does not apply inside one group. An optometrist and surgeon in the same practice bill the global code once, without 54 or 55.
Where Co-Management Turns Into Risk
Co-management is legal, but regulators watch it closely because it pays the provider who referred the patient. The AAO compliance guidance and First Coast point to the same safeguards:
- Patient choice comes first. The patient must request or agree to co-management, and the decision must be clinically right for that case.
- No routine arrangements. Transferring every patient from a referring practice by default looks like a referral incentive, and Medicare does not cover transfers made that way.
- No extra payments. All payment should flow through the 54 and 55 claims. Fees paid to a co-manager outside the claim, or days shifted to inflate their share, can draw Anti-Kickback scrutiny.
- Premium lens charges stay separate. Patient-paid amounts for advanced lenses follow their own rules, covered in our premium IOL billing guide, and are not a way to pay the co-manager.
Correct modifier use is part of the same picture. Our overview of medical billing modifiers explains how 54, 55 and 56 fit with the rest, and the optometry billing cheat sheet lists the codes optometrists bill outside the global.
One Patient, Two Practices, Zero Claim Conflicts
Cataract co-management billing pays both offices fairly only when their claims mirror each other. The surgeon bills 54 with the transfer date, the co-manager bills 55 with the days actually provided, and a signed agreement and patient consent sit behind both. Second eyes, combined procedures and plans that ignore the modifiers are where that mirror usually cracks.
Ophthalmology practices that share cases with optometrists can hand that reconciliation to MBW RCM. Its ophthalmology billing services match each 54 claim to its 55 partner, confirm the payer accepts co-management and check the date spans before either office files a claim.
Cataract Co-Management Billing FAQs
What is modifier 56 in cataract surgery?
Modifier 56 reports preoperative management only, when a different provider handles the pre-op evaluation. It is rarely used in ophthalmology, where the surgeon normally performs the pre-op exam.
Can the co-managing optometrist bill on the day of surgery?
No. The 55 claim uses the surgery date as the date of service, but it can be submitted only after the co-manager has provided the first post-op visit.
What happens if the patient returns to the surgeon during the global?
Both offices adjust their claims. The co-manager’s date span ends when care returns, and the surgeon bills 55 for the days they resume.
Does modifier 55 apply when no transfer agreement exists?
No. Without a written transfer, Medicare expects the surgeon to bill 54, and a non-group clinician who sees the patient post-op may report G0559 once per global period.