CPT Code 99213 — Complete Guide to Billing, Documentation & Reimbursement

What Is CPT Code 99213?

CPT code 99213 is an Evaluation and Management (E&M) procedure code used to bill for an established patient office or other outpatient visit that involves either a low level of medical decision-making (MDM) or a minimum of 20 minutes of total time spent on the date of the encounter.

Published by the American Medical Association (AMA) and maintained in the CPT code set, 99213 is one of the most frequently billed codes across primary care, internal medicine, and specialty practices. Understanding its definition, documentation requirements, and appropriate use is critical for both compliance and revenue optimization.

CPT 99213 Definition: The Official Description

CPT 99213 description:

Office or other outpatient visit for the evaluation and management of an established patient, which requires a medically appropriate history and/or examination and low level of medical decision making. When using total time on the date of the encounter for code selection, 20 minutes must be met or exceeded.

In plain terms: 99213 applies when a provider sees a patient they’ve treated before and the clinical complexity falls within the low MDM tier or when the provider spends at least 20 minutes on that encounter date.

Code at a glance:

What Is an Established Patient?

Before billing 99213, confirm the patient qualifies as established. The AMA defines an established patient as one who has received professional services from the physician, or from another physician of the same specialty in the same group practice, within the past three years.

If the patient is new to your practice, you must use the new patient E&M series (99201–99205). Billing 99213 for a new patient is a common and auditable coding error.

CPT 99213 Time Requirement (2024 Rules)

A major update from CMS’s 2021 E&M guidelines revision fully in effect for 2024 changed how time can be used to select outpatient E&M codes.

99213 time requirement: 20 minutes total time on the date of encounter.

This means providers can count:

• Pre-visit preparation (reviewing records, test results)
• Face-to-face encounter time
• Post-visit work (care coordination, documentation, ordering, communication with other providers)

All time must occur on the same calendar date as the encounter. Time spent on other days does not count toward 99213’s 20-minute threshold.

This is a meaningful change: previously, only face-to-face time counted. Today, if a provider spends 25 minutes on a visit (12 minutes with the patient, 13 minutes reviewing labs and writing notes), 99213 or potentially a higher level may be appropriate based on total time.

Low Medical Decision Making (MDM): The Other Path to 99213

If you prefer to select E&M level by MDM rather than time, 99213 requires a low level of medical decision-making, defined by three components problems addressed, amount of data reviewed/ordered, and risk of complications.

For low MDM, the encounter must meet two of the three elements:

1. Problems Addressed

• Two or more self-limited or minor problems, OR
• One stable chronic illness, OR
• One acute, uncomplicated illness or injury

Examples: seasonal allergies follow-up, stable hypertension monitoring, uncomplicated UTI.

2. Amount and/or Complexity of Data Must meet ONE of the following:

• Reviewed a minimum of three unique data sources (e.g., ordered one test, reviewed external records, and independently interpreted a test result)
• OR independently interpreted results of a test ordered by another provider

3. Risk of Complications and/or Morbidity or Mortality

• Low risk: prescription drug management for stable, well-controlled conditions

If the encounter’s complexity exceeds these thresholds for example, a patient presents with two or more chronic illnesses requiring active monitoring you may be looking at CPT 99214 (moderate MDM) instead.

CPT 99213 vs 99214: Key Differences

One of the most searched comparisons in medical coding: 99213 vs 99214. Getting this distinction right is both a compliance and a revenue issue.

Undercoding 99214 encounters as 99213 is among the most widespread (and costly) revenue leakage patterns AffinityCore’s billing auditors identify across primary care and internal medicine practices. If your documentation supports moderate MDM or ≥30 minutes, 99213 leaves real reimbursement uncollected.

CPT 99213 vs 99212: When to Step Down

On the other end: 99212 vs 99213 decisions matter for compliance too. Overcoding billing 99213 when only minimal MDM is warranted creates audit exposure.

Factor	CPT 99212	CPT 99213
MDM Level	Minimal	Low
Time Threshold	10 minutes	20 minutes
Problem Type	1 self-limited/minor problem	Multiple minor or 1 stable chronic
Data Review	Minimal or none	Meets low MDM
Typical Use	Simple medication refill, brief check-in	Routine chronic disease management

A quick medication refill with no clinical review, no data interpretation, and no risk assessment fits 99212. Routing it to 99213 without documentation support creates payer audit vulnerability.

ICD-10 Code Pairing: What You Need to Know

CPT 99213 is a procedure code it describes the service rendered, not the diagnosis. Every 99213 claim must be paired with at least one valid ICD-10 diagnosis code that supports the medical necessity of the visit.

There is no single “ICD-10 code for 99213” rather, 99213 can be billed with any ICD-10 code that clinically justifies the level of service. Common pairings include:

• Z00.00 — General adult medical examination without abnormal findings (annual wellness)
• I10 — Essential (primary) hypertension
• E11.9 — Type 2 diabetes mellitus without complications
• J06.9 — Acute upper respiratory infection, unspecified
• F41.1 — Generalized anxiety disorder

The diagnosis code(s) must be supported by clinical documentation in the medical record. Payers including Medicare may deny or flag claims where the stated diagnosis doesn’t align with the services documented.

Medicare Reimbursement for CPT Code 99213

Medicare reimbursement for 99213 is determined by the Medicare Physician Fee Schedule (MPFS) and varies by geographic location (Medicare locality) and facility setting.

2024 National Average Rates (approximate):

Setting	Non-Facility (Office)	Facility (Hospital/FQHC)
Medicare Payment	~$78–$92	~$57–$68

• Geographic adjustment (GPCI — Geographic Practice Cost Indices)
• Modifier use (e.g., -25 with a procedure on the same day)
• Payer contract rates (commercial payers negotiate above or below Medicare)
• Claim accuracy (errors reduce or eliminate payment)

To find your practice’s exact allowable, check the CMS Medicare Physician Fee Schedule Lookup Tool. For commercial payer rates, review your individual contract fee schedules.

Systematic underpayments where payers reimburse below contracted rates for 99213 are a frequently overlooked revenue leak. AffinityCore’s billing audit services include payer contract compliance review to flag these discrepancies.

99213 Documentation Requirements: What Must Be in the Chart

For a 99213 claim to withstand payer scrutiny or a CMS audit, the medical record must clearly support the level billed. Under the 2021 AMA/CMS E&M guidelines (applicable through 2024 and beyond), documentation requirements have been simplified and now focus on medical necessity rather than counting bullets.

If billing by MDM, document:

• The problems addressed in the encounter
• Any data reviewed, ordered, or analyzed (clearly describe which sources)
• The management decisions and associated risk level

If billing by time, document:

• The total time spent on the date of the encounter
• A brief description of the activities included in that time

You no longer need to document a specific number of history elements or exam bullet points to justify 99213 but your note must still be clinically coherent, complete, and support the diagnosis codes billed.

Common documentation errors AffinityCore auditors find in 99213 claims:

• Time documented without specifying what activities were included
• MDM complexity overstated relative to the presenting problem
• Missing or vague diagnosis documentation
• No indication of data reviewed when data-based MDM is claimed
• Copy-paste notes that don’t reflect the actual visit

99213 and Telehealth Billing

CPT 99213 is an approved telehealth-eligible code. When billing 99213 for a telehealth encounter, providers must:

• Append modifier 95 (synchronous telehealth service) for most payers
• Ensure the patient was seen via real-time audio-video communication (audio-only has different requirements)
• Follow state-specific telehealth billing rules, which vary by payer

Medicare telehealth reimbursement for 99213 follows the same fee schedule rates as in-person visits (policy as extended through recent legislation verify current CMS guidance for your billing period).

99213 and Transitional Care Management (TCM)

If a patient was recently discharged from a hospital or post-acute care facility, providers may be considering Transitional Care Management (TCM) codes (99495 or 99496) instead of a standard E&M code like 99213. TCM codes generally offer higher reimbursement and reflect the additional coordination work involved in post-discharge care.

You cannot bill both a TCM code and a standard E&M code (such as 99213) for the same encounter date. If TCM criteria are met, billing 99213 for that visit is a compliance error and an underutilization of available revenue.

Common 99213 Billing Errors and Compliance Risks

Medical billing audits consistently surface the same 99213-related errors. Recognizing them is the first step toward correction.

1. Billing 99213 for new patients Using the established patient code for a new patient is a misuse of the code. If the patient hasn’t been seen by the practice (or by a same-specialty provider in the group) within three years, they are new and require the 99201–99205 series.

2. Insufficient documentation for MDM level selected Claiming low MDM without documentation that supports at least two of the three MDM components. Auditors look for clinical evidence vague or templated notes don’t support this.

3. Time-based billing without time documentation If you select 99213 on the basis of time (≥20 min), that time must be explicitly stated in the note, along with what activities were performed.

4. Modifier -25 overuse When a minor procedure is performed on the same visit, modifier -25 allows 99213 to be billed separately but the E&M service must be a significant, separately identifiable service from the procedure. Blanket use of -25 without separate documentation is an audit trigger.

5. Diagnosis code mismatch Pairing a chronic condition ICD-10 code with documentation that only mentions an unrelated acute complaint or vice versa raises claim integrity issues.

6. Consistent overcoding patterns If your practice overwhelmingly bills 99213 over 99212 or 99211, or consistently selects 99213 where 99214 might apply, statistical outlier analysis by payers can trigger a probe audit.

How AffinityCore’s Medical Billing Audit Protects Your 99213 Revenue

AffinityCore‘s medical billing audit services are built to identify exactly the types of coding, documentation, and compliance issues described in this guide before your payers find them.

Our certified coding and billing specialists audit your E&M claim patterns, including 99213, across several dimensions:

Coding Accuracy Review We verify that each 99213 claim is supported by documentation that meets either the MDM or time-based threshold and flag claims where a different code level would be more accurate.

Revenue Leakage Identification Many practices systematically underbill established patient visits. Our auditors identify patterns where 99213 is used when documentation supports 99214 recovering revenue that would otherwise be forfeited.

Payer Contract Compliance We compare your actual reimbursements against contracted rates to identify underpayments a common but often invisible revenue drain.

Denial Pattern Analysis If your 99213 claims are generating denials at above-average rates, we pinpoint the root cause: documentation gaps, modifier errors, diagnosis mismatches, or eligibility issues.

Compliance Risk Mitigation We proactively identify billing patterns that create audit exposure protecting your practice from costly recovery audits by Medicare or commercial payers.

Whether you’re a primary care practice, a multi-specialty group, or a healthcare system, an accurate 99213 coding posture is foundational to your revenue cycle health.

Related Services & Content from AffinityCore

Looking to optimize your full billing workflow beyond CPT 99213? Explore AffinityCore’s connected services:

• Medical Coding Services — Expert CPT and ICD-10 coding for all specialties, including E&M leveling and review
• Denial Management Services — Root-cause analysis and resolution for denied E&M and procedure claims
• Revenue Cycle Management Services — End-to-end RCM from charge capture through collections
• AR Recovery Services — Recover outstanding revenue on aged 99213 and other E&M claims
• Internal Medicine Billing — Specialty billing support for the practice types that bill 99213 most frequently
• Charge Entry Services — Accurate charge capture to ensure 99213 is entered and submitted correctly

Frequently Asked Questions

What is CPT code 99213?

CPT 99213 is an E&M code for established patient office visits requiring low medical decision-making or at least 20 minutes of total encounter time.

What is the time requirement for CPT 99213?

CPT 99213 requires a minimum of 20 minutes of total provider time on the date of the encounter, including pre-visit, face-to-face, and post-visit activities.

What is the Medicare reimbursement rate for CPT code 99213?

Medicare reimburses approximately $78–$92 for CPT 99213 in a non-facility setting. Exact rates vary by geographic location and are updated annually in the Medicare Physician Fee Schedule.

What is the difference between CPT 99213 and 99214?

CPT 99213 requires low medical decision-making or 20 minutes. CPT 99214 requires moderate decision-making or 30 minutes, and typically reimburses $30–$50 more per visit.

Can CPT 99213 be used for new patients?

No. CPT 99213 is only for established patients seen within the past three years. New patients must be billed under codes 99202–99205.