An internal medicine group we work with hired a third physician last fall, and the new patient vs established patient question caught them within a month. The front desk did what front desks do: every patient booked with the new doctor was scheduled as a new patient, and the visits went out as 99204. In January the Medicare remits came back with CO-B16, "new patient qualifications were not met," on about a third of them. The patients weren't new. They had seen one of the other two internists in the same group within the last three years, and Medicare's claims history knew it even though the scheduler didn't.
The same group had the opposite problem hiding in its established visits. A patient last seen in November 2022 came back in January 2026 and was billed as 99213 because the chart already existed. That visit qualified as new. This looks like the simplest question in E/M coding, and practices get it wrong in both directions because the rule has three parts and most staff know one.
A glossary line for readers who don't code: E/M means evaluation and management, the office visit codes. New patient office visits are CPT 99202 to 99205 and established patient visits are 99211 to 99215, and the new patient codes pay more at every level. Whether a visit is new or established is not a clinical judgment; it is a set of facts about who saw the patient, where they work and when.
Key takeaways
- A patient is new only if no physician or qualified health professional of the exact same specialty and subspecialty in the same group has provided a face-to-face professional service in the past three years.
- The three years run from the last date of service to the current date of service, not from the date the chart was created.
- For Medicare, a nurse practitioner or physician assistant is treated as the same specialty as the physician they work with, so a visit with the NP two years ago makes today's physician visit established.
- Hospital, nursing facility and telehealth visits by a group physician count as professional services even when they never appear in the office system.
- The denial to watch is CARC B16; the money to watch is the established visits that should have been billed as new.
New patient vs established patient: the CPT definition
The CPT E/M guidelines define a new patient as one who has not received any professional services from the physician or other qualified health care professional, or from another physician or qualified health care professional of the exact same specialty and subspecialty who belongs to the same group practice, within the past three years. Everyone else is established. We break that sentence into four tests and run them in order.
Test one is the professional service. CPT defines professional services as face-to-face services reported by specific CPT codes. An office visit counts. A hospital admission counts. A video visit billed as an office E/M counts. A physician reading an EKG or an X-ray without seeing the patient does not count, and the Medicare Claims Processing Manual says the same. A nurse phone call, a portal refill request and a records request do not count either.
Test two is the group, which for Medicare means the tax identification number the claim is billed under. Test three is the specialty and subspecialty: the patient who saw the endocrinologist in your multispecialty group two years ago is new to your family physician, while the patient who saw your former partner, another family physician, is established even though your new physician has never met them. Test four is time: three years, counted from the last qualifying date of service.
Counting the three years without a calendar mistake
The clock starts on the date of the last face-to-face professional service, not the first one, and runs to the date of the current visit. Practice management systems display the "patient since" date, the account creation date and the last statement date prominently, and none of them is the date we need, which is the last date of service on a claim from a physician of the same specialty under the same TIN.
A worked example. A patient was seen by Dr. Alvarez, a family physician, on January 15, 2023, and by nobody else in the group since. On February 3, 2026, the patient sees Dr. Chen, a family physician who joined the group in 2025. More than three years have passed, so the visit is new and 99203 or 99204 is correct if the documentation supports it. Move the 2023 visit to March 10, 2023, and the same February 2026 visit becomes established. Same patient, same chart, different code.
The reverse error costs more than the denial does, because nobody sends you a remit for it. Most systems default the visit type to established the moment a chart exists, so a patient not seen in three years and two months gets billed at the lower level. A primary care office that runs the report finds a handful every month.
| Situation | New or established | Why |
|---|---|---|
| Saw a partner of the same specialty 2 years ago, first visit with this physician | Established | Same group, same specialty, within 3 years |
| Saw the group's endocrinologist last year, first visit with the family physician | New | Different specialty |
| Group cardiologist read the patient's EKG 18 months ago, never saw the patient | New | Interpretation only is not a face-to-face service |
| Group hospitalist admitted the patient 14 months ago, now an office visit with a same-specialty physician | Established | Hospital E/M is a professional service |
| Saw the group NP 2 years ago, first visit with the supervising physician (Medicare) | Established | Medicare treats the NP as the physician's specialty |
| Last visit 3 years and 1 month ago, chart still open | New | More than 3 years since the last service |
Same group, same specialty: where the test gets hard
Medicare decides specialty by the code the physician enrolled under in PECOS, the Medicare enrollment system, not by what the physician calls themselves. Two physicians enrolled as internal medicine are the same specialty even if one practices only diabetes care. Medicare has separate enrollment codes for some subspecialties, interventional cardiology for instance, and not for others, so the answer for a group's cardiologists depends on how each enrolled. Commercial payers usually work from the taxonomy code on the claim and the specialty in the credentialing file.
The nurse practitioner and physician assistant rule catches many practices. The Medicare Claims Processing Manual says that when advanced practice nurses and physician assistants work with physicians, they are considered to be working in the exact same specialty and subspecialty as the physician. A patient who saw the NP for a sinus infection two years ago is established when the physician sees them for the first time today. Some commercial payers treat NPs as their own specialty; unless the payer has told you so in writing, assume the Medicare approach.
Two more rules. When a physician is on call or covering for another physician, CPT says the visit is classified as it would have been by the physician who is unavailable, and the same applies to locum tenens physicians billing under your physician's number. And the hardest cases are encounters that never touch the office system: a group hospitalist who admitted the patient last year, an urgent care visit at a site your group owns, a weekend telehealth visit. The payer's claims history sees all of them even when your scheduler cannot.
The denials this causes and what they cost
The denial code is CARC B16, "new patient qualifications were not met," usually with group code CO. Medicare contractors run an edit against the beneficiary's claims history for the same specialty under the same TIN, and many commercial payers do the same. Some deny the line and wait for a corrected claim; others pay the established equivalent and leave a remark. Either way the fix is the same: rebill the corresponding established code, 99202 to 99212, 99203 to 99213, 99204 to 99214, 99205 to 99215, with the same documentation.
The money is real but not dramatic per claim. Suppose a payer allows $155 for 99203 and $115 for 99213, and $225 for 99204 and $165 for 99214; those are illustrative numbers, not any payer's schedule. The denials cost little beyond a thirty to sixty day delay, because they get corrected and paid. The visits billed as established when the patient qualified as new lose $40 to $60 each, permanently once timely filing closes, and twenty of them a month is roughly $1,000 a month that no report flags.
The rule also governs preventive visits, 99381 to 99387 for new patients and 99391 to 99397 for established, and it decides consult requests for Medicare patients, since Medicare stopped paying office consultation codes in 2010 and a referred patient is simply new or established under the three-year test. When a payer denies B16 and you believe the patient is genuinely new, the usual cause is a prior visit by a different-specialty physician in your group that the payer's edit lumped together. Appeal with the CPT definition and the enrollment specialty of both providers rather than filing a corrected claim you don't agree with.
Setting the flag in the practice management system
The visit type is decided at scheduling and rarely questioned afterward, so the fix belongs at the front desk and in the system, not with the coder. Most practice management systems can flag new versus established automatically from the last date of service by rendering provider specialty. Check what the flag keys on: a system that keys on the individual provider marks every patient new to a new physician, which is exactly the error the internal medicine group made.
Schedulers need one sentence of training: "new to this doctor" is not "new patient." We give front desks a card with three questions: has anyone in our group of the same specialty seen this patient, was it face to face, and was it within three years. If the answer is unknown, schedule as established and let the coder upgrade it if the history supports new. Then audit it monthly with two reports, new patient claims with a prior same-specialty visit and established claims without one. Our RCM training courses cover this in the E/M module because it is the most common E/M error we see in new biller audits, and it is entirely mechanical.
Questions we hear
The patient saw our NP two years ago and is seeing the physician for the first time. New or established?
For Medicare, established. For commercial payers, established unless the payer has published a policy treating NPs as a separate specialty. When in doubt, bill established; the underpayment risk is a single level.
The patient only came in for a flu shot given by our nurse. Does that make them established?
Under a strict reading of CPT, a nurse-only vaccine visit with no E/M is not a professional service by a physician or qualified health professional. Payer edits don't read that carefully; expect a B16 if you bill new and be ready to appeal with the definition. If the nurse visit was billed as 99211, the patient is established, because 99211 is an E/M service reported under the physician.
We have been refilling the patient's prescriptions for four years but haven't seen them. Are they new?
Yes. Refills, portal messages and phone calls are not face-to-face professional services. If the last face-to-face visit with a same-specialty physician in your group was more than three years ago, the patient is new. The chart being open changes nothing.
What to do this week
- Pull all new patient claims from the last 90 days and check each against your group's same-specialty claims history for the prior three years.
- Pull established visits from the same period where the prior same-specialty visit is more than three years back, and rebill any within timely filing.
- Confirm the enrollment specialty code for every physician, NP and PA in PECOS and in your commercial credentialing files.
- Configure the practice management system's automatic new-patient flag, keyed on specialty rather than individual provider.
- Give schedulers the three-question card and add a B16 line to the monthly denial report so the error shows up as a trend.
