What is the difference between a split/shared visit and incident-to billing?

In incident-to billing, only the NP/PA sees the patient (the physician is on-site but does not personally examine the patient). In a split/shared visit, both the physician AND the NP/PA personally see and examine the patient on the same day. The billing framework is different: incident-to requires 5 specific Medicare criteria, while split/shared requires the billing provider to perform the "substantive portion" defined by time or MDM.

How does CMS define the substantive portion for split/shared visits?

CMS offers two pathways: (1) Time-based — the billing provider must account for more than 50% of the total encounter time, or (2) MDM-based — the billing provider must personally perform 2 of the 3 MDM elements (problems addressed, data reviewed/analyzed, and risk of management). The practice can choose whichever pathway yields the higher compliant code.

Is modifier -FS required for all split/shared visits?

Modifier -FS is required for facility-based split/shared visits (hospital inpatient, ED, observation, SNF). For non-facility (office) split/shared visits, CMS does not currently require modifier -FS as of 2024-2026, though documentation must still clearly establish the split/shared nature. Commercial payers may have different modifier requirements — check payer-specific guidelines.

Can the physician bill a split/shared visit if the NP spent more total time?

Yes — if using MDM-based coding. Under the MDM pathway, the physician can bill if they performed 2 of the 3 MDM elements, regardless of who spent more total time. This is common in workflows where NPs handle history-taking, data gathering, and documentation (time-intensive) while physicians perform the clinical decision-making (MDM-intensive). If using time-based coding, the provider with the majority of time must bill.

Split/Shared Visits: The 2024–2026 Rules for Physician + NPP Encounters

A physician and an NP see the same patient on the same day. The physician spends 15 minutes; the NP spends 30 minutes. Who bills? Under whose NPI? At what rate? The answer to these questions — which changed significantly under CMS’s 2024 final rule — determines whether your practice collects 100% or 85% of the Medicare fee schedule for that encounter.

Split/shared visits are one of the most financially impactful and most misunderstood billing scenarios in medicine. Get them right, and you bill every qualifying encounter at the full physician rate. Get them wrong, and you face recoupments, denials, and audit liability. This guide covers the current 2024–2026 CMS rules, documentation requirements, and how AI determines which provider should bill.

What Is a Split/Shared Visit?

A split/shared visit occurs when both a physician and a non-physician practitioner (NPP) — an NP or PA — personally perform substantive portions of an E/M visit for the same patient on the same day, in the same group practice.

Key distinctions from incident-to billing:

Incident-to: Only the NPP sees the patient. Billed under the physician’s NPI because the physician initiated the treatment plan and is on-site.
Split/shared: Both the physician AND the NPP personally see the patient during the same encounter. Billed under whichever provider performs the “substantive portion.”

Split/shared visits can occur in any facility or non-facility setting: office, hospital inpatient, ED, observation, SNF, or home visits.

The 2024–2026 CMS Rule: “Substantive Portion”

CMS’s current rule (effective January 1, 2024) defines who bills a split/shared visit based on the substantive portion:

If Selecting Time-Based Coding

The billing provider must account for more than half of the total time spent on the encounter. Both providers document their individual time, and the one with the majority bills under their NPI.

Example:

NP spends 20 minutes (history, exam, care coordination)
Physician spends 25 minutes (MDM, counseling, care plan)
Total time: 45 minutes
Physician performed >50% of total time → bills under physician NPI at 100% rate
45 total minutes on an established patient = 99215 (40–54 minutes)

If Selecting MDM-Based Coding

The billing provider must personally perform the substantive portion of the MDM. CMS defines this as performing 2 of the 3 MDM elements:

Number and complexity of problems addressed
Amount and/or complexity of data to be reviewed and analyzed
Risk of complications and/or morbidity or mortality of patient management

The provider who personally performs at least 2 of these 3 elements is the billing provider.

Example:

NP collects history, reviews external records (data element)
Physician addresses 3 chronic conditions (problems element) and initiates drug therapy requiring monitoring (risk element)
Physician performed 2 of 3 MDM elements → bills under physician NPI
MDM level: moderate (multiple chronic conditions + prescription drug management) = 99214

Why the 2024 Rule Matters: What Changed

Before 2024, CMS proposed that the billing provider must perform the “substantive portion,” defined as more than half of total time in ALL cases — even when coding by MDM. This would have eliminated the ability to bill under the physician when the NP spent more total time but the physician performed the critical MDM work.

The final 2024 rule preserved the dual pathway: you can define “substantive portion” by EITHER time (majority) OR MDM (2-of-3 elements). This is significant because:

Many split/shared encounters involve the NP spending more total time (history, exam, documentation) while the physician performs the high-complexity MDM (diagnosis, risk assessment, treatment decisions)
Under the MDM pathway, the physician can bill even with less total time, as long as they perform 2-of-3 MDM elements
This preserves revenue for practices where physicians handle decision-making while NPPs handle data gathering

Documentation Requirements for Split/Shared Visits

CMS requires specific documentation beyond the standard E/M note:

1. Both Providers Must Document

Each provider must have their own documentation in the medical record. A single note signed by both providers is insufficient. The auditor must be able to see:

What the NP/PA personally performed
What the physician personally performed
When each provider saw the patient (same calendar day)

Acceptable formats:

Two separate notes (one from each provider)
A single note with clearly delineated sections identifying which provider performed which elements
One provider’s note with a documented addendum by the other

2. Time Documentation (If Billing by Time)

When using time-based coding for a split/shared visit, document:

Total time each provider spent on the encounter (not just face-to-face — total time on the calendar date)
Activities each provider performed during their time
Combined total time for code selection

Template language: “I personally spent 25 minutes on this encounter including: reviewing records (5 min), face-to-face with patient (15 min), care coordination with specialist (5 min). NP [Name] spent 20 minutes including: obtaining history (10 min), physical exam (5 min), order entry (5 min). Total encounter time: 45 minutes. I performed the substantive portion (>50% of total time).”

3. MDM Documentation (If Billing by MDM)

When using MDM-based coding, document which provider performed which MDM elements:

Who addressed the problems (assessed conditions, made diagnoses)
Who reviewed and analyzed the data (labs, imaging, external records)
Who determined and managed the risk (treatment decisions, prescriptions)

Template language: “Split/shared visit with NP [Name]. I personally performed: assessment of 3 chronic conditions (problems), initiation of new medication with monitoring requirements (risk). NP [Name] performed: review of outside hospital records and recent labs (data). I performed the substantive portion of MDM (2 of 3 elements).”

4. Same Group Practice

Both providers must be in the same group practice (same tax ID). A physician cannot split/share with an NP from a different practice, even if they are both treating the patient in the same facility.

Modifier Requirements

CMS modifier requirements for split/shared visits:

Facility settings (hospital, ED, SNF): Append modifier -FS (Split/Shared E/M Visit) to the E/M code when billing under the physician’s NPI for a split/shared encounter. This modifier was introduced in 2022 and is currently required for facility-based split/shared visits.
Non-facility settings (office): As of 2024–2026, CMS does not require modifier -FS for office-based split/shared visits. However, documentation must still clearly establish the split/shared nature and the substantive portion.
Commercial payers: Modifier requirements vary. Some commercial payers require -FS in all settings; others do not recognize it. Check payer-specific guidelines before submitting.

Important: Modifier -FS does not reduce payment. It is an informational modifier that identifies the claim as a split/shared visit for audit and tracking purposes.

Revenue Impact: The Math

The financial case for proper split/shared billing:

If the NP bills under their own NPI: 85% of MPFS. A 99214 pays approximately $131 (2024 Medicare national average for NPs).
If billed under physician NPI as split/shared: 100% of MPFS. The same 99214 pays approximately $155.
Difference per encounter: ~$24

For a practice where the physician performs the substantive portion on 8 split/shared visits per day:

8 encounters × $24 = $192/day
250 working days = $48,000/year in additional revenue from coding correctly

Combined with incident-to billing for encounters where only the NPP sees the patient, a practice with 2–3 NPs can capture $100,000–$300,000 in additional annual revenue by billing each encounter under the correct framework.

Split/Shared vs Incident-To: When to Use Each

Scenario	Billing Method	Rate
Only NP sees patient, physician on-site, established problem	Incident-to	100%
Both physician and NP see patient same day, physician does substantive portion	Split/shared (physician bills)	100%
Both physician and NP see patient same day, NP does substantive portion	Split/shared (NP bills)	85%
Only NP sees patient, new problem or physician not on-site	NP bills under own NPI	85%

The optimal workflow: physicians focus their time on the highest-complexity MDM decisions (problems + risk elements), while NPs handle data gathering, history, exam, and documentation. This naturally positions the physician to perform 2-of-3 MDM elements — qualifying them as the billing provider at the 100% rate.

Common Compliance Mistakes

Mistake 1: Physician Signs But Doesn’t Personally Perform

Problem: The physician co-signs the NP’s note without personally seeing the patient or performing any MDM elements. This is not a split/shared visit — it’s a co-signature on an NP encounter and must be billed under the NP’s NPI at 85%.

Fix: The physician must have their own documented, face-to-face component with the patient. A co-signature alone never converts an NP visit to a physician-billed split/shared encounter.

Mistake 2: No Time or MDM Attribution

Problem: The note documents a split/shared visit but doesn’t specify who performed which elements or how much time each provider spent. An auditor cannot determine the “substantive portion.”

Fix: Use the template language above. Explicitly state which MDM elements or time activities each provider performed. The note should make it obvious to an auditor — without needing to call the provider for clarification.

Mistake 3: Billing Physician for All Split/Shared Encounters

Problem: Practice bills all split/shared visits under the physician regardless of who performed the substantive portion. If the NP actually did most of the work (both time and MDM), billing under the physician is non-compliant.

Fix: Evaluate each encounter individually. If the NP performed the substantive portion (majority of time OR 2-of-3 MDM elements), the NP must bill under their own NPI. Not every split/shared visit should be billed under the physician.

Mistake 4: Confusing Split/Shared With Incident-To

Problem: If both providers saw the patient, it is NOT incident-to (where only the NPP sees the patient). Billing as incident-to when both providers had face-to-face time is incorrect and can trigger audit flags for inconsistent documentation.

Fix: If the physician personally saw and examined the patient, use the split/shared framework. Incident-to is only for encounters where the NPP is the sole provider of the face-to-face service.

How AI Determines Which Provider Should Bill

CodeItRight’s AI engine can analyze split/shared visit documentation and determine the correct billing provider:

Time calculation: The AI extracts documented time for each provider, calculates the total, and identifies which provider exceeded 50%. If the physician has the majority, it recommends billing under the physician NPI with the appropriate time-based code.
MDM element attribution: The AI identifies which provider performed which MDM elements (problems addressed, data reviewed, risk managed). If the physician performed 2-of-3, it recommends physician billing with the MDM-based code.
Dual-pathway comparison: The AI calculates the code under both time and MDM for each provider, then recommends the combination that yields the highest compliant reimbursement.
Documentation gap flagging: If the note doesn’t clearly attribute elements to specific providers, the AI flags it as insufficient for split/shared billing and identifies what additional documentation is needed.
Modifier reminder: For facility-based encounters, the AI recommends appending modifier -FS when the split/shared criteria are met.

Inpatient and ED Split/Shared Visits

Split/shared visits are particularly common (and valuable) in hospital settings:

Hospital inpatient: The NP rounds on patients, gathers data, and documents findings. The physician reviews, makes treatment decisions, and briefly sees the patient. If the physician performs the substantive portion, the visit bills under the physician at the higher facility rate.
Emergency department: The NP performs initial evaluation, orders, and stabilization. The physician performs definitive MDM (diagnosis, disposition, risk assessment). Physician bills the ED E/M code (99281–99285) with modifier -FS.
Observation: Similar to inpatient — both providers document their contributions, and the one with the substantive portion bills under their NPI.

In hospital settings, the modifier -FS is required on split/shared claims. Omitting it risks denial or audit flags.

The Bottom Line

Split/shared visits represent one of the largest untapped revenue opportunities for practices that employ both physicians and NPPs. The 2024–2026 CMS rules are clear: the provider who performs the substantive portion — defined by either majority of time OR 2-of-3 MDM elements — bills under their NPI. When practices structure workflows so that physicians handle the highest-complexity MDM decisions, they can legitimately bill split/shared encounters at the 100% physician rate.

The key is documentation. Both providers must clearly document what they personally performed. Without clear attribution of time or MDM elements, the encounter defaults to the NP’s NPI at 85% — or worse, faces audit liability for unclear billing. AI-powered split/shared analysis eliminates the guesswork by extracting each provider’s contributions and recommending the correct billing configuration before submission.