Multispecialty Group Billing · CY2026

Two clinicians, one encounter, and only one right way to bill it in 2026.

If your physicians and APPs share visits, split/shared and incident-to are not interchangeable. They live in different settings, demand different supervision, and credit a different name on the claim. Here is the side-by-side, updated for the CMS CY2026 Physician Fee Schedule.

The short answer

Use split/shared in facility settings (hospital, ED, outpatient departments) and let the substantive portion decide who bills. Use incident-to only in the office/non-facility setting, under direct physician supervision, and only for an already-established plan of care. Mix them up and you either leave 15% on the table or invite a takeback.

Why this matters now

Four numbers to hold in your head before January

No fabricated benchmarks here, just the structural facts that drive the money on a shared encounter.

100%

of the fee schedule when the physician is the billing clinician (either pathway)

85%

when the APP bills a split/shared visit under their own NPI

conversion factors for CY2026 (QP vs non-QP), a first for the MPFS

the modifier that must ride every split/shared claim line

The comparison matrix

Split/shared vs incident-to, line by line

Read down each column for one billing pathway. Read across each row to see exactly where the two rules diverge on the same shared encounter.

Condition

Facility

Split / Shared

FS modifier

Office

Incident-To

Direct supervision

Setting

Facility / institutional only: hospital inpatient and observation, outpatient departments, emergency department, SNF. Not the office.Place of service = facility

Non-facility office only (POS 11) and patient home in limited cases. Never in a hospital or facility setting.Place of service = office

Supervision

Both practitioners are in the same group and same facility for the same patient on the same date. No physical in-room supervision test.Shared work, same day

Direct supervision: the physician is present in the office suite and immediately available. CY2026 continues the virtual (real-time audio-video) direct supervision allowance for defined services.Physician in the suite

Who gets credited

The practitioner who performs the substantive portion bills the visit under their own NPI.Substantive portion wins

Always billed under the supervising physician's NPI, even though the APP delivered the care.Physician's NPI

Payment rate

Physician bills = 100%. APP bills = 85% of the MPFS amount.100% or 85%

100% of the MPFS amount, because the physician is the billing clinician.Always 100%

New / established

Works for new and established patients and for most E/M levels, including many ED and hospital visits.New OK

Established patients only, on a physician-initiated plan of care. A new problem needs the physician's own visit first.Established only

Documentation trigger

Note must show both clinicians' work and identify who did the substantive portion (time or MDM). Append modifier FS.Attribution note + FS

Note must show the physician's ongoing involvement and the established plan; supervising physician linked on the claim.Link the physician

Quality credit

Performance attributes to the billing NPI, which shifts MIPS/MVP attribution if the APP bills.Follows the biller

Attributes to the physician, keeping MVP measure credit with the supervising clinician.Follows the physician

The definition that decides the money

"Substantive portion" in the CY2026 final rule

For split/shared visits, CMS finalized keeping the flexible definition of substantive portion. You can qualify by time or by medical decision making, and you pick whichever the encounter actually supports.

Pathway A

More than half the total time

The billing clinician personally spent over 50% of the combined time on the visit that day. Document the time split so the attribution is defensible.

TIME > 50% of the shared total

Pathway B

A substantive part of the MDM

The billing clinician performed a substantive part of the medical decision making. CY2026 preserves MDM as a valid basis, so a physician who owns the decision can bill even without owning the clock.

MDM = substantive part

Either path qualifies. Critical care split/shared is time-based by its own rule, so keep that carve-out in your edits.

Decision flow

Which pathway applies? Four questions.

Run every shared encounter through this before the coder ever sees it.

Where did the visit happen?

Facility (hospital, ED, HOPD, SNF) points to split/shared. Office points to incident-to.

Facility → split/shared

Is the problem new or established?

A new problem in the office cannot be incident-to. The physician must see it first, or bill under the APP.

New office problem → APP visit

Was the physician immediately available?

Incident-to needs direct supervision in the suite. No physician available means the APP bills at 85%.

No supervision → 85% APP

Who did the substantive portion?

For split/shared, time or MDM names the biller. Physician → 100% and modifier FS. APP → 85% and modifier FS.

Attribution → NPI + FS

MPFS · CY2026

Two conversion factors, and why your APP mix now moves the number

For the first time, the CY2026 Physician Fee Schedule finalized two conversion factors, reflecting the 2.5% statutory update and the higher update path for qualifying participants in advanced APMs. Whether the physician or the APP is the billing clinician changes both the payment percentage and which clinician's participation status applies.

Pair that with MVP participation: the Quality Payment Program keeps expanding MIPS Value Pathways, and attribution follows the billing NPI. If your APPs bill more shared visits, measure credit and scoring move with them.

CY2026 CF · QP

Higher

Qualifying APM participants, per the finalized higher update path

CY2026 CF · Non-QP

Lower

Everyone else, on the standard finalized update

APP split/shared

85%

When the APP is the billing clinician

Physician either way

100%

Split/shared or incident-to

Confirm the exact CY2026 conversion-factor dollar values against the CMS final rule before you load them into your fee schedule. The structure above is fixed; the decimals belong to the published rule.

Where groups lose the money

Five failure points we see on shared visits

Incident-to in a facility

Billing incident-to on a hospital or HOPD encounter. That rule does not exist there. It is split/shared.

Missing modifier FS

A clean split/shared visit with no FS modifier reads as an ordinary E/M and undoes your attribution trail.

New problem, incident-to

An APP handling a brand-new complaint in the office and billing under the physician. The plan was never established.

No attribution in the note

The note shows both clinicians but never states who did the substantive portion. The 100% claim is exposed on audit.

Supervision not documented

Incident-to billed while the physician was out of the suite, with nothing showing direct supervision was met.

Guidelines cited in this piece

CMS Calendar Year 2026 Medicare Physician Fee Schedule (PFS) final rule, split/shared visit and substantive-portion policy
CMS incident-to and direct supervision policy, including the CY2026 virtual (real-time audio-video) direct supervision allowance
Medicare Physician Fee Schedule conversion factors for CY2026 (qualifying vs non-qualifying APM participant)
Medicare Claims Processing Manual, split/shared and incident-to billing and modifier FS
Quality Payment Program: MIPS Value Pathways (MVP) participation and attribution to the billing clinician

Your shared visits should bill themselves.

ASP-RCM builds the setting, supervision, and attribution checks straight into your coding and edits, so split/shared and incident-to route correctly before a claim ever leaves the building. Fewer takebacks, cleaner MVP attribution, every clinician credited right.

Talk to ASP-RCM about your APP billing