CY2026 MPFS · Split (or Shared) E/M

Two clinicians, one patient, one claim. Who bills it?

The provider who performed the substantive portion gets the claim. In 2026 that is settled two ways: more than half of the total time, or a substantive part of the medical decision making. Pick one per visit, document it, and append Modifier FS.

Who billsThe physician or the NPP who did the substantive portion. Not seniority. Not who signed first.

How you measureTime (more than 50% of total) OR medical decision making. One measure, chosen per encounter.

Where it appliesFacility place of service only. The office (POS 11) is never a split/shared visit.

The rule in four numbers

What CY2026 actually locked in

>50%

of total time is the time-based threshold for the substantive portion

valid measures: total time or medical decision making (MDM)

the modifier that flags every split/shared claim on the line

415.140

42 CFR section that defines the visit and the facility requirement

The unique angle

Route the encounter to the right billing provider

A physician and a nonphysician practitioner in the same group both see the patient during one facility encounter. Walk it down. Each gate has one answer, and the last gate is the only one that decides the name on the claim.

Gate 1 · Setting

Is the place of service a facility?

Inpatient, hospital outpatient, ED, observation, SNF. If this is an office visit (POS 11), stop: it is billed under normal incident-to rules, not split/shared.

Gate 2 · Same group

Are both practitioners in the same group and specialty arrangement?

A split/shared visit is a physician and an NPP in the same group jointly furnishing one E/M service to the same patient on the same date.

Gate 3 · Pick the measure

Are you scoring this visit by time or by MDM?

Choose one for this encounter. Critical care (99291/99292) is the exception: it can only be scored by time.

Gate 4 · The decider

Who performed the substantive portion?

By time: who spent more than half the total. By MDM: who did the substantive part of the decision making. That practitioner is the billing provider.

Substantive portion = physician

Bill under the physician

Physician NPI on the claim, full fee schedule. Append Modifier FS. Physician documents and signs the portion they performed.

Substantive portion = NPP

Bill under the NPP

NPP NPI on the claim at the applicable NPP payment percentage. Append Modifier FS. NPP documents and signs their portion.

Non-negotiable: the billing practitioner must personally document the portion of the service they performed, and both practitioners' notes live in the same medical record for the same date of service.

Substantive portion, defined

Time or MDM. Choose one, then be consistent.

Path A Total time

Whoever personally spends more than half of the combined qualifying time is the billing provider. Overlapping minutes are counted once, not twice.

Example: physician 22 min of 34 total = 65% → physician bills

Only counts face-to-face and qualifying non-face-to-face time on that date
The single required measure for critical care split/shared visits
Cleanest to defend on audit when the time log is contemporaneous

Path B Medical decision making

Whoever performs the substantive part of the MDM is the billing provider, even if they spent less clock time. Retained from the CY2024 policy and carried into CY2026.

Example: NPP gathers data, physician sets the diagnosis and risk plan → physician bills on MDM

The practitioner billing must have performed two of the three MDM elements
Ordering, interpreting, and owning the risk decision are the anchor
Cannot be used for critical care, which is time-only

The gate people forget

Facility place of service is a hard requirement

Split/shared billing exists because facility settings do not allow incident-to billing. That is the whole point. Run the POS code before you run the substantive-portion test. Green codes qualify. Red does not.

Inpatient hospital

On-campus outpatient

Off-campus outpatient

Emergency department

Skilled nursing (Part A)

Office — not split/shared

Where the claim breaks

The denials we see on split/shared lines

What happened	Why it denies	The fix
Visit billed under the physician on reputation, not measurement	Substantive portion not supported	Score every encounter by one measure and document who met it
Modifier FS left off the E/M line	Missing split/shared indicator	Append FS to every split/shared E/M claim, no exceptions
Office visit coded as split/shared	Setting ineligible	Confirm a facility POS before applying the rule at all
Billing provider never wrote in the note	No personal documentation	The billing practitioner signs the portion they personally performed
Critical care split by MDM	Wrong measure for the code	Score 99291/99292 split/shared by time only
Time counted twice while both were in the room	Inflated total time	Count overlapping minutes once toward the total

One rule, thousands of encounters, real dollars per line

Across a multispecialty group, the split/shared decision fires on hospital rounds, ED consults, and observation stays every single day. Get the substantive-portion call right and the claim clears at the correct rate under the correct NPI. Get it wrong and it is a slow bleed of takebacks. ASP-RCM Solutions builds the routing logic into your charge capture and audits it against the CY2026 rule so the name on the claim is always the one that did the work.

Talk to ASP-RCM about your split/shared workflow

Guidelines cited

CY2026 Medicare Physician Fee Schedule Final Rule (CMS-1832-F), split (or shared) evaluation and management visit policy
42 CFR 415.140, definition of split (or shared) E/M visits and the facility setting requirement
Substantive-portion definition allowing total time or medical decision making, finalized in the CY2024 MPFS Final Rule and continued for CY2026
Modifier FS, split (or shared) E/M service reporting indicator
Critical care (CPT 99291, 99292) split/shared visits measured by time only, per CMS billing policy

This page is billing guidance for multispecialty group revenue teams and is not legal advice. Verify current-year specifics against the published final rule for your dates of service.

Two clinicians, one patient, one claim. Who bills it?

What CY2026 actually locked in

Route the encounter to the right billing provider

Time or MDM. Choose one, then be consistent.

Path A Total time

Path B Medical decision making

Facility place of service is a hard requirement

The denials we see on split/shared lines

One rule, thousands of encounters, real dollars per line

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