Add-on code
A code that cannot be coded by itself and must accompany a primary service, describing additional work performed during the same encounter (for example, a prolonged-service or psychotherapy add-on).
APP
Advanced Practice Provider. A collective term for clinicians such as nurse practitioners (NPs) and physician assistants (PAs) who evaluate and manage patients. Used in this guide alongside physician to refer inclusively to everyone who documents and codes clinical care.
AWV
Annual Wellness Visit. A Medicare preventive service focused on health-risk assessment and care planning. It is not a head-to-toe physical examination.
CMS
Centers for Medicare and Medicaid Services. The federal agency that runs Medicare and Medicaid and publishes the Physician Fee Schedule, including the RVUs and payment rules most coding decisions reference.
Conversion factor
The dollar figure Medicare multiplies by a code's total RVUs to set the payment amount. It is updated annually.
CPT
Current Procedural Terminology. The standardized code set, maintained by the American Medical Association, that describes the services and procedures a clinician performs. Every codable encounter is reported with one or more CPT codes.
DRG
Diagnosis-Related Group. A classification used to determine hospital payment for an inpatient admission, driven heavily by the documented diagnoses and comorbidities.
E/M
Evaluation and Management. The family of codes (such as 99202 to 99215) describing office and other non-procedural visits where the work is cognitive: history, examination, and medical decision making.
Global period
A window of time after a procedure (commonly 0, 10, or 90 days) during which related routine care is bundled into the procedure's payment and not separately codable.
G2211
A Medicare add-on code recognizing the ongoing, longitudinal nature of a continuing care relationship, codable with many office E/M visits.
Incident-to
A Medicare coding arrangement under which a service performed by an APP is coded under a supervising physician, at the physician rate, when specific conditions are met.
MDM
Medical Decision Making. The measure, since 2021, that determines the level of most office visits, scored across three elements: the problems addressed, the data reviewed, and the risk of the management plan.
Modifier
A two-character suffix appended to a code that adds information about the service, for example that an evaluation was distinct from a same-day procedure (Modifier 25) or that a procedure was unrelated to a prior surgery (Modifier 79).
PFS
Physician Fee Schedule. The Medicare schedule listing the RVUs and payment rules for each CPT code, published and revised annually.
Preventive visit
A wellness-focused visit (such as an annual physical or the Medicare AWV) coded separately from problem-oriented E/M work.
Prolonged services
Codes capturing time spent on a visit beyond the threshold of the highest standard E/M level on a given day.
Provider
Used throughout this guide to mean physicians, nurse practitioners, physician assistants, and other clinicians who document and code patient care.
RVU
Relative Value Unit. The unit Medicare uses to measure the resources a service requires. Total RVUs combine three components: work, practice expense, and malpractice.
Split/shared visit
A hospital or facility encounter in which both a physician and an APP perform part of the work on the same day; rules determine under whom it is coded.
TCM
Transitional Care Management. Services coordinating a patient's care in the days after discharge from a hospital or facility.
Taxonomy
A code identifying a clinician's specialty or subspecialty, which can affect whether two clinicians in the same group are treated as the same specialty for new-versus-established patient purposes.
wRVU
Work Relative Value Unit. The work component of a code's total RVUs, and the figure most often used to measure clinician productivity and to calculate production-based compensation.
NCCI (National Correct Coding Initiative)
The Medicare edit system that decides which code pairs can be reported together on the same day, and which combinations bundle. When two procedures deny together, the reason is usually an NCCI edit.
ICD-10
The diagnosis code set. Every CPT service on a claim is justified by one or more ICD-10 diagnosis codes; the diagnosis explains why the work was medically necessary.
HCC and risk adjustment
Hierarchical Condition Categories. A payment model in which documented chronic diagnoses adjust the expected cost of a patient. In value based arrangements, undocumented comorbidities lower the measured complexity of your panel.
POA (Present on Admission)
A hospital reporting indicator marking whether a condition existed at admission. It affects hospital quality metrics and payment, and depends on physician documentation at the time of admission.
Modifier 57 (Decision for Surgery)
Appended to the E/M visit at which the decision was made to perform a major procedure (90 day global) that day or the next day, so the visit pays separately instead of bundling into the global package.
Modifier 24 (Unrelated E/M During a Global Period)
Appended to a visit during another procedure's global period when the visit addresses a problem unrelated to that procedure, so the visit pays despite the global.