Incident-To vs. Split/Shared Services (Medicare E&M Billing)

Context & Key Terminology

• Medicare-specific rules dominate this topic; when the speaker says “incident-to” or “split/shared,” assume CMS rules unless another payer is explicitly mentioned.
  • Other carriers (Aetna, UHC, etc.) may say they “follow incident-to guidelines,” but their policies can diverge.
  • Best practice: call all non-Medicare scenarios “advanced-practitioner billing” to avoid confusion.
• Preferred label for non-MD/DO clinicians: Advanced Practitioner (AP) or Nurse Practitioner (NP) / Physician Assistant (PA) rather than “Non-Physician Practitioner (NPP)” or “mid-level.”

Incident-To Services (Office/Clinic Only)

• High-level definition
  • Service performed by an AP but billed under the supervising physician’s National Provider Identifier (NPI) as though the physician personally delivered it.
• Why use it? 100\% Medicare physician fee schedule (vs. 85\% if billed under the AP’s own NPI).
• Core CMS criteria (all must be satisfied)
  • Initiation by Physician: Physician conducts the initial visit, establishes diagnosis & plan of care (POC).
  • Direct Supervision (same office suite, immediately available)
  • Physician need not enter exam room, but must be on-site.
  • Vacation, hospital rounds, or Aruba ≠ direct supervision ➔ service fails incident-to.
  • Continuity & Same Problem Rule
  • Follow-up must address the exact condition in the original POC.
  • Any new problem → Requires new physician visit before future incident-to billing.
  • Non-Facility Setting Only
  • Allowed: private office, rural health clinic, physician-owned clinic.
  • Not allowed: hospital inpatient, hospital outpatient departments, SNF, other institutional sites.
• Practical example
  • Visit 1: Dr. Smith diagnoses low-back pain, writes detailed POC.
  • Visit 2: NP Rachel performs follow-up while Dr. Smith is in the office ➔ bill incident-to.
  • Scenario change: Patient during Visit 2 complains of new shoulder pain ➔ cannot bill incident-to; physician must evaluate shoulder first.
• Common pitfalls & audit flags
  • Billing under a physician on vacation or off-site.
  • Using a scheduling “grid” only; ignoring POC initiation & same-problem rules.
  • Lack of documentation showing physician involvement beyond the first visit.

Split / Shared E&M Services (Facility-Based)

• High-level definition
  • Same calendar day, both physician & AP each provide medically necessary portions of one Evaluation & Management (E/M) service.
  • Service may be billed under either practitioner’s NPI depending on who performed the substantial portion.
• Settings allowed
  • Hospital inpatient, observation, ED, hospital outpatient clinics, SNF (Part B), etc. (Office use uncommon; office usually uses incident-to instead.)
• Operational requirements
  • Same-Day Rule: Two separate encounters on different days cannot be combined.
  • Medically Necessary Work by Each
  • Both document distinct, non-duplicative contributions (history, exam, medical decision-making, counseling, etc.).
  • Determining billing provider
  • Component-based approach: Whose work meets the substantial portion standard (historically, majority of history/exam/MDM—now tied to time or MDM).
  • Time-based approach (2023+ guidance): Add total minutes spent face-to-face + non-face-to-face on day of encounter. If physician > 50\% of total time ➔ physician NPI (100 %); otherwise AP NPI (85 %).
• Documentation essentials
  • Clear delineation: “Dr. Lee spent 20 min reviewing diagnostics & finalizing plan; PA Brown spent 15 min obtaining full history & exam.”
  • Single combined note acceptable if roles/time/MDM are explicitly attributed to each provider.
• Example
  • Morning: PA performs comprehensive history & exam (25 min).
  • Afternoon: Physician reviews, adjusts meds, discusses plan with patient & family (35 min).
  • Total time = 60 min; physician = 35 min (>50\%) ➔ bill under physician NPI at 100 %.

Incident-To vs. Split / Shared — Fast Comparison

• Location
  • Incident-To: Office / freestanding clinic.
  • Split/Shared: Facility (hospital inpatient/outpatient, ED, SNF, etc.).
• Who sees patient?
  • Incident-To: Only AP on DOS; physician saw initial visit.
  • Split/Shared: Both AP and physician, same day.
• Supervision requirement
  • Incident-To: Direct (physician on-site).
  • Split/Shared: No direct on-site requirement; merely both contributing same calendar day.
• Billing NPI & Reimbursement
  • Incident-To: Always physician NPI ⇒ 100\%.
  • Split/Shared: Whichever provider did substantial portion; physician = 100\%, AP = 85\%.

Compliance, Ethical & Practical Considerations

• Financial incentive vs. risk
  • Incorrect incident-to billing → potential overpayment, penalties, false-claims exposure.
• Terminology matters: Mislabeling AP services as “incident-to” when payer is non-Medicare can confuse staff and auditors.
• Organizational policy
  • Some practices deliberately avoid incident-to to sidestep audit risk; they accept 85\% payment.
• Provider respect & morale
  • “Non-Physician Practitioner” label can feel dismissive; using AP/NP/PA fosters inclusivity.

Tips, Best Practices & Quick-Check Questions

• Maintain a living roster/calendar showing which supervising physicians are physically present daily.
• Embed incident-to checklist in EHR: POC initiated? Same problem? Direct supervision? Continuity documented?
• For split/shared, use time stamps or separate attestations: “Dr. X spent __ min; NP Y spent __ min.”
• Train coders to flag notes mentioning new problems during incident-to follow-ups.
• During audits, verify:
  • Presence of physician note in initial encounter (incident-to) or same-day contribution (split/shared).
  • Correct site of service code (office vs. facility).

Key Numbers & Formulas to Memorize

• Medicare AP reduction: 85\% of Physician Fee Schedule.
• Physician rate when criteria met: 100\% of Physician Fee Schedule.
• Substantial-portion threshold under time method: physician time > 50\% of total → physician billing.