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Almost everything in E/M coding is a judgement call. This is not. Whether a patient is new or established is a determinate question with one right answer, decidable from the schedule and the practice’s own records before the patient is seen — and it is got wrong constantly, because the rule is usually remembered as “have we seen them in three years?” when the actual test has four moving parts and three of them are about the clinician, not the patient.
The stakes are ordinary but relentless. New-patient visits carry higher work values than established-patient visits at every level, so a systematic error in either direction compounds across every clinic day, and it is trivially detectable on review because it depends on facts that are entirely in the practice’s own records.
Verified against the American Medical Association’s CPT Evaluation and Management (E/M) Code and Guideline Changes, effective 1 January 2023 — the E/M Services Guidelines sections “New and Established Patients” and “Initial and Subsequent Services,” and the Instructions for Use of the CPT Codebook coding tip reproduced there — and against CMS Medicare Learning Network booklet MLN006764, Evaluation and Management Services (May 2026 revision). CPT codes, descriptions and other data are copyright the American Medical Association. Individual payers may apply additional enrolment or credentialing rules on top of the CPT definition.
The Rule, Verbatim
The definition is one sentence, and every clause in it does work:
“A new patient is one who has not received any professional services from the physician or other qualified health care professional or another physician or other qualified health care professional of the exact same specialty and subspecialty who belongs to the same group practice, within the past three years.”
And its mirror:
“An established patient is one who has received professional services from the physician or other qualified health care professional or another physician or other qualified health care professional of the exact same specialty and subspecialty who belongs to the same group practice, within the past three years.”
“Professional services” is defined immediately before, and narrowly:
“Solely for the purposes of distinguishing between new and established patients, professional services are those face-to-face services rendered by physicians and other qualified health care professionals who may report evaluation and management services.”
The Four Tests
Decomposed, the rule asks four questions. A patient is established only if the answer to all four is yes.
| # | Test | What it turns on |
|---|---|---|
| 1 | Was a professional service rendered? | Face-to-face, by someone who may report E/M services |
| 2 | Within the past three years? | Date to date |
| 3 | By you, or by someone of the exact same specialty and subspecialty? | Subspecialty, not just specialty |
| 4 | Who belongs to the same group practice? | The billing group, not the building |
Tests 3 and 4 are conjunctive. Both must hold. A partner in your group of a different subspecialty does not make the patient established; neither does a same-subspecialty colleague in a different group. This is the single most misstated part of the rule, usually collapsed into “anyone in our practice.”
Test 1: face-to-face, and by whom
Two exclusions follow directly from the definition. A service that was not face-to-face — a telephone call, an interpretation of a study performed elsewhere, a record review — does not make the patient established, because “professional services” for this purpose are face-to-face services only.
And the person must be someone who may report E/M services. The guidelines define the category and its counterpart precisely:
“A ‘physician or other qualified health care professional’ is an individual who is qualified by education, training, licensure/regulation (when applicable), and facility privileging (when applicable) who performs a professional service within his or her scope of practice and independently reports that professional service. These professionals are distinct from ‘clinical staff.’ A clinical staff member is a person who works under the supervision of a physician or other qualified health care professional, and who is allowed by law, regulation and facility policy to perform or assist in the performance of a specific professional service but does not individually report that professional service.”
So a nurse-only visit, a phlebotomy appointment or a medical assistant’s blood-pressure check does not start the three-year clock. The distinguishing feature is who independently reports the service.
Test 2: three years, measured plainly
The text says “within the past three years.” It does not say three calendar years, or three years from 1 January, or thirty-six months of eligibility. It is date to date. A patient last seen on 14 March 2023 is established on 13 March 2026 and new on 15 March 2026.
Test 3: exact same specialty and subspecialty
The word “exact” is in the CPT text and is not decorative. Two clinicians in the same group who are both internists but one of whom is a gastroenterologist and the other a cardiologist are not of the same subspecialty. A patient seen by the cardiologist last year is a new patient to the gastroenterologist — same group, same base specialty, different subspecialty.
This is the test that most often produces under-coding. Practices that treat a shared chart as proof of an established relationship systematically bill established-patient levels for encounters that are genuinely new-patient work, which is precisely the intra-specialty referral within a multispecialty group.
Test 4: same group practice
“Group practice” is about the entity under which the service is reported, not physical proximity. Independent practices sharing a building or an EHR instance are not one group practice. Conversely, a large group’s satellite office fifty miles away is the same group practice.
The Two Rules That Override the Obvious Answer
Advanced practice nurses and physician assistants
The guidelines state this three separate times, which is a fair indication of how often it is missed:
“When advanced practice nurses and physician assistants are working with physicians, they are considered as working in the exact same specialty and subspecialty as the physician.”
A patient seen last year by the nurse practitioner working with your cardiology group is an established patient to the cardiologist. There is no separate “NP specialty” for this test. This is where practices most commonly over-code, by treating an APP encounter as though it had never happened.
Covering and on-call clinicians
“In the instance where a physician or other qualified health care professional is on call for or covering for another physician or other qualified health care professional, the patient’s encounter will be classified as it would have been by the physician or other qualified health care professional who is not available.”
The locum or covering clinician inherits the absent clinician’s status with the patient. You classify the encounter as the person you are covering for would have classified it — not by your own history with the patient, and not by your own group membership.
Where the Rule Does Not Apply
The emergency department
“No distinction is made between new and established patients in the emergency department. E/M services in the emergency department category may be reported for any new or established patient who presents for treatment in the emergency department.”
Categories that use initial versus subsequent instead
Hospital inpatient and observation care, and nursing facility services, do not sort by new and established. They sort by whether the service is initial or subsequent, and the test is structurally parallel but bounded by the admission rather than by three years:
“An initial service is when the patient has not received any professional services from the physician or other qualified health care professional or another physician or other qualified health care professional of the exact same specialty and subspecialty who belongs to the same group practice, during the inpatient, observation, or nursing facility admission and stay.”
The same specialty/subspecialty and group-practice qualifiers apply, and so do the covering and APP rules. Two definitions of “stay” are worth noting: “a stay that includes a transition from observation to inpatient is a single stay,” and for nursing facilities, “a stay that includes transition(s) between skilled nursing facility and nursing facility level of care is the same stay.” Where a status change is involved, the coding question sits alongside the utilisation-review one — see the two-midnight rule and condition code 44.
Worked Cases
The multispecialty group referral
A patient is seen by Dr A, a rheumatologist, in a large multispecialty group in June 2025. In February 2026 the same group’s Dr B, a nephrologist, sees her on internal referral.
Same group practice: yes. Exact same specialty and subspecialty: no. New patient to Dr B. The shared chart, shared billing entity and internal referral are all irrelevant to the test.
The nurse practitioner encounter
A patient is seen by Ms C, a physician assistant working with a dermatology practice, in September 2024. In January 2026 she sees Dr D, a dermatologist in that practice, for the first time.
Ms C is treated as working in the exact same specialty and subspecialty as the physicians she works with. A face-to-face professional service was rendered within three years by the same group. Established patient to Dr D.
The locum
Dr E covers Dr F’s clinic for a fortnight. A patient of Dr F’s, last seen by Dr F eight months ago, attends and is seen by Dr E, who has never met her and is not a member of Dr F’s group.
The covering rule controls: classify the encounter as Dr F would have. Established patient.
The interpretation-only contact
A radiologist in a group reads a patient’s CT in 2024. In 2026 the patient attends that group’s interventional radiology clinic for a face-to-face consultation with a colleague of the same subspecialty.
The 2024 read was not a face-to-face service, so it did not render a professional service for this purpose. Whether the patient is new turns on whether any qualifying face-to-face encounter occurred — the imaging interpretation alone does not make her established. Where the professional component was separately reported, the modifier 26 and TC split describes what was actually billed.
The three-year edge
A patient was last seen by the same clinician on 2 May 2023. She books for 2 May 2026.
Exactly three years. “Within the past three years” is satisfied on the anniversary itself, so she remains established on 2 May 2026 and becomes new from 3 May 2026. If a practice’s policy is to treat the anniversary as new, that policy is billing a higher-valued code on the one day the text does not support it.
Frequently Asked Questions
Does a telehealth visit make a patient established?
The E/M guidelines govern services requiring a face-to-face encounter with the patient and/or family or caregiver, and a real-time audio-video encounter is generally treated as satisfying that requirement for the service being reported. Which code family and modifier apply is a separate question — see modifier 95 and 93 and the GT and G0 modifiers. Payer policy on telehealth and patient status varies more than the CPT text does, so check the specific plan before relying on it.
What if the previous visit was billed to a different insurer, or self-pay?
Irrelevant. The test is whether a face-to-face professional service was rendered, not how or whether it was paid.
What if the previous encounter was a preventive visit?
A preventive medicine service delivered face-to-face by a clinician who may report E/M services is a professional service. It starts the clock. See the preventive versus problem visit guide for how the two services interact on a single date.
Does a no-show or a cancelled appointment count?
No. No face-to-face service was rendered.
Who decides what counts as a subspecialty?
CPT does not publish a subspecialty list for this purpose, which is why practices should document their own reasoning and be consistent. Payers frequently look to the specialty designation under which the clinician is enrolled, and Medicare contractors in particular tend to reason from the enrolled specialty code. Where your internal view and the payer’s enrolment record diverge, expect the enrolment record to drive the edit.
Does incident-to billing affect the answer?
Incident-to is a payment rule about who may bill for a service, not a definition of who rendered it. A service performed by an APP and billed under a physician’s number was still a face-to-face professional service. See the incident-to guide for the conditions that rule imposes, which are independent of the new-versus-established test.
Should this be checked before the visit or after?
Before. Every fact the rule depends on is in the practice’s own systems: prior encounter dates, the rendering clinician, that clinician’s subspecialty and group. A front-desk or scheduling check is cheap, and a determinate rule decided after the fact is the kind of finding that extrapolates across a sample.
Why This Is Worth Getting Right
Because it is checkable. A reviewer disputing your MDM level has to argue about clinical judgement against the MDM table. A reviewer disputing new-patient status just pulls your own encounter history and compares dates and specialties. There is no defence to offer if the facts do not support it, which makes this the least rewarding place in E/M coding to be approximately right — and one of the easiest to make exactly right with a scheduling-stage check.
