Split/Shared Visit Billing: 7 Rules for 2026

A split/shared visit is a single evaluation and management (E/M) visit that a physician and a nonphysician practitioner in the same group both take part in, in a facility setting, where Medicare pays the one who did the larger share of the work. Only one claim goes out, under one name, and the rule for 2026 decides whose name it is: the practitioner who performed the substantive portion of the visit bills it, and the claim carries modifier FS. This is the hospital and skilled nursing counterpart to incident-to billing, which governs the office. Get the setting wrong, or the modifier, or the documentation, and the claim is either denied or paid to the wrong provider.

For an independent practice that is adding physician assistants or nurse practitioners, this is worth understanding before the first split/shared visit, not after a denial. Below are seven rules that cover who may bill a split/shared visit, how the substantive portion is measured, and where the rule does and does not apply.

What is a split/shared visit, and who bills it?

Medicare describes a split/shared visit as an E/M visit that a physician and a nonphysician practitioner in the same group each help furnish, where either one could have billed the service on their own had they performed it alone. Because two providers contribute, Medicare needs a tie-breaker for whose National Provider Identifier goes on the claim. That tie-breaker is the substantive portion. The practitioner who performed it bills the split/shared visit and is paid for it; the other provider’s work supports the record but does not generate a separate claim. The eligible nonphysician practitioners are nurse practitioners, physician assistants, clinical nurse specialists, and certified nurse midwives, per the American College of Surgeons’ summary of the policy.

The reason this matters more every year is the shape of the workforce. The American Association of Nurse Practitioners reported more than 461,000 licensed nurse practitioners in the United States as of its November 2025 count, and the Bureau of Labor Statistics projects nurse practitioner employment to grow 41 percent between 2025 and 2035, about 137,800 new jobs. More practices are pairing a physician with an NPP on the same patient, so more visits fall under this rule than used to.

Rule 1: It only applies in facility settings

The consensus across the Medicare Administrative Contractors is clear and worth stating plainly: split/shared billing is a facility rule. Novitas, a Medicare Administrative Contractor, describes the covered settings as the institutional places where incident-to billing is prohibited, which means hospital inpatient and outpatient departments and skilled nursing facilities. The office is not one of them. In the office and other non-facility settings, the equivalent arrangement is incident-to billing under direct supervision, which is a different rule with different conditions. Some skilled nursing facility visits that regulation requires a physician to perform cannot be shared at all. The emergency department follows separate rules, so confirm those with your contractor before you apply this guidance to an ED encounter.

Here is the distinction most independent practices miss, and it is the one we draw for the practices we support on in-office diagnostics. The vascular and autonomic testing a practice runs in its own office, for example the ankle-brachial and heart-rate-variability battery performed on a CMAT Advantage system, is produced at the point of care in the office. That is a non-facility setting. Split/shared visit rules never reach it. In-office diagnostic work follows the diagnostic-test supervision rules and, for the E/M visit around it, incident-to or direct billing, never the facility substantive-portion test. Knowing which rulebook a given encounter sits under is the whole game, and it turns on where the patient was seen.

Rule 2: One practitioner bills, based on the substantive portion

A split/shared visit still produces one E/M code and one claim. What changes is whose name it goes out under. Medicare pays the provider who performed the substantive portion, and that provider is the one who signs the claim. If the physician did the substantive portion, the visit is billed under the physician at the full fee schedule rate. If the nonphysician practitioner did it, the visit is billed under the NPP, which Medicare pays at 85 percent of the fee schedule amount. That payment difference is real money over a year of split/shared visits, so the substantive-portion determination is not a formality. It should be made from the record of what each provider actually did, not from habit or convenience.

Rule 3: Substantive portion means time or medical decision making

Since January 1, 2024, Medicare has let a practice define the substantive portion in one of two ways, and that definition still stands for 2026. The substantive portion is either more than half of the total time the two providers spent on the split/shared visit, or a substantive part of the medical decision making. A practice picks whichever fits the encounter. For a long counseling visit, time is often the cleaner measure. For a complex problem where one provider set the plan, medical decision making usually tells the truer story.

When a practice uses medical decision making, the provider who bills has to be the one who made or approved the management plan for the problems addressed and who takes responsibility for that plan, per the American College of Surgeons’ reading of the rule. Medical decision making cannot be split down the middle and half-credited. One provider owns it, and that provider bills.

Rule 4: Append modifier FS to the claim

Every split/shared E/M claim carries HCPCS modifier FS, described as “split (or shared) evaluation and management visit.” The modifier is how Medicare knows the encounter was shared rather than furnished by one provider alone, and it belongs on the E/M line whether the physician or the NPP ends up billing. Leaving it off is a common, quiet error: the claim may still pay, but it misrepresents the encounter and will not hold up on audit. Build the FS modifier into the template for shared encounters so it is not left to memory on a busy day.

Rule 5: Document both providers, and have the biller sign

The medical record has to identify both the physician and the nonphysician practitioner who took part in the split/shared visit. Novitas states that the individual who performed the substantive portion, and who therefore bills, must personally sign and date the record. A co-signature from a provider who did not do the substantive work does not move the claim to that provider. If the documentation does not show who did what, the determination of who may bill falls apart, and so does the claim on review. Write the note so that a reader who was not in the room can see which provider carried the split/shared visit.

Rule 6: Count joint time once, and watch critical care

When a practice bills a split/shared visit on time, the time the two providers spend together counts only once, not twice. If the physician and the NPP are in the room with the patient at the same moment, that shared stretch is a single block of time, not a doubled one. Total time can include the usual E/M activities, such as reviewing history, examining the patient, counseling, ordering tests and referrals, documenting, and interpreting results. It excludes services that are reported separately, travel, and time spent teaching.

Critical care is the clear exception. Critical care services, CPT 99291 and 99292, are reported on time alone, with no medical decision making option, so for a split/shared visit the substantive portion in critical care is simply who spent more than half the total critical care time. Keep that case separate in your head and in your templates, because the two-option rule does not apply to it.

Rule 7: Match the rule to the setting

Most billing errors around shared care come from using the wrong rulebook for the setting. The short version is easy to carry. In a hospital or skilled nursing facility, a visit two providers share is a split/shared visit, billed by whoever did the substantive portion, with modifier FS. In the office, that same pairing is governed by incident-to billing and, for any diagnostic test, by the diagnostic-test supervision rules. A practice that runs in-office diagnostics and bills E/M visits in both the office and a facility has to keep both rulebooks straight, because the setting, not the staff, decides which one applies.

If adding ancillary services is part of the plan, it helps to see how these billing rules sit alongside the broader economics. Our guides on ancillary revenue for medical practices, coding an in-office diagnostic encounter, and billing a same-day E/M with modifier 25 cover the pieces that most often sit next to a split/shared visit on the schedule.

Frequently asked questions

Can a shared E/M visit be billed in the office?

No. This rule is for facility settings, mainly hospital inpatient and outpatient departments and skilled nursing facilities. In the office and other non-facility settings, a physician and an NPP working together fall under incident-to billing and direct supervision instead, which is a separate rule with its own conditions.

What is the substantive portion for 2026?

It is either more than half of the total time the two providers spent on the split/shared visit, or a substantive part of the medical decision making. A practice may use whichever applies to the encounter. This two-option definition has been in effect since January 1, 2024, and it continues for 2026.

What modifier goes on a shared visit?

Modifier FS, “split (or shared) evaluation and management visit,” goes on the E/M line of every split/shared visit claim, whether the physician or the nonphysician practitioner ends up billing.

Who can take part in a shared E/M visit?

A physician and a nonphysician practitioner in the same group. Medicare recognizes nurse practitioners, physician assistants, clinical nurse specialists, and certified nurse midwives as the nonphysician practitioners for this purpose.

Does this apply to our in-office vascular or autonomic testing?

No. In-office diagnostic testing is produced in a non-facility setting and follows the diagnostic-test supervision rules, with the surrounding E/M visit billed under office rules. The facility substantive-portion test does not reach work performed in your own office.

Getting shared-visit billing right in your practice

HealthWright Technologies helps independent practices add in-office diagnostic testing and bill it correctly, with practical billing guidance that draws the line between what belongs in the office and what belongs in a facility. If you are weighing how in-office diagnostics and split/shared visit billing fit together on your schedule, you can reach us through our contact page or email contact@healthwrighttechnologies.com, and you can call and we will follow up.

This article is general information for practice billing, not coding, legal, or reimbursement advice, and payer rules change. Confirm current policy with your Medicare Administrative Contractor before you bill. CPT is a registered trademark of the American Medical Association.

Coverage questions often turn on the GA, GX, GY and GZ liability modifiers, which signal when a service may not be paid.