Medical coding is a key component of revenue cycle management (RCM). It involves translating patient health information from physician’s notes, diagnoses, and procedures into universal alphanumeric CPT, HCPCS and ICD-10 codes. Accurate medical coding is essential for capturing each patient’s health story, helping to support important healthcare functions. Using the appropriate codes optimizes medical billing and insurance claims processing, helps maintain patient records, and ensures accurate reimbursement for healthcare services. Many practices rely on professional medical coding services for accurate documentation and communication of patient care. Whether you outsource medical coding or perform it in-house, our tips and best practices can help ensure accuracy, reduce errors, improve compliance, and maximize timely reimbursement.
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Tips for Precise ICD-10 and CPT Coding
Medical coding and billing require a unique set of skills and knowledge. From attention to detail, knowledge of medical terminology and coding systems to analytical and communication skills, and awareness about insurance policies and payer rules, several aspects are essential for success in the field.
Here are six best practices for avoiding medical coding errors, and ensuring accurate billing and reimbursement:
- Use Checklists
Medical coding involves translating a provider’s impressions, judgments, and actions regarding diagnosis, treatments, and results into reportable ICD-10, HCPCS and CPT codes. The benefits of using coding checklists include:
- Reminds coders to include additional characters, action and add-on codes, necessary modifiers, and other details, reducing the risk of rejections
- Helps stay updated with ICD-10, CPT, and HCPCS code changes
- Minimizes errors caused by distractions
- Saves time on corrections and rework
- Promotes standardized claim submission in line with payer requirements
- Supports compliance by flagging mandatory quality and tracking codes
- Reduce risk of audits, penalties, and legal issues that result from non-compliance or billing inaccuracies
- Improves team communication and supporting better coordination among healthcare professionals
Checklists are especially useful for accurate Evaluation & Management (E/M) coding, which is complex due to changing documentation requirements, evolving guidelines, time component requirements, and different levels of service.
- Accurate Documentation of Review of Systems
The Review of Systems (ROS) refers to a systematic review of body systems obtained by asking a series of questions to identify signs and/or symptoms the patient may be experiencing or has experienced. ROS is a key component of medical documentation that directly impacts coding accuracy and the level of service billed. Such queries made verbally by the physician, hospital staff, or patient intake forms help to check requirements for extended examination and testing.
The Centers for Medicare and Medicaid Services (CMS) recognizes 14 systems for a Review of Systems (ROS). For coding purposes, the completeness of the ROS helps determine the level of E/M service:
- A problem-pertinent ROS involves reviewing one system related to the current complaint.
- An extended ROS covers two to nine systems.
- A complete ROS includes ten or more systems.
Accurate documentation of the ROS ensures that the provider’s work is correctly reflected in the medical record and supports appropriate reimbursement. Missing or incomplete ROS details can lead to downcoding and revenue loss, while over-documentation can trigger compliance issues. Consistent use of templates or checklists can help maintain accuracy, prevent omissions, and ensure that documentation aligns with payer and regulatory requirements.
- Appropriate Use of Modifiers
Certain CPT and HCPCS codes require modifiers to provide additional information about the procedure performed. Modifiers can also be used to identify the body area where the procedure was performed, such as modifier RT for “right side” and LT for “left side”.
Assigning appropriate medical coding modifiers now require greater attention due to various reasons:
- Payer use of AI-driven audits: AI instantly flags modifier misuse
- Increased scrutiny to detect unbundling errors: Modifiers like -59 (Distinct Procedural Service) and the X-modifiers (XE, XS, XP, XU) are under additional scrutiny because they tend to be misused or overused to bypass National Correct Coding Initiative (NCCI) edits and obtain payment for services that would otherwise be bundled.
- Evolving telehealth policies: Coders must ensure accurate use of telehealth modifiers like 95 (synchronous telehealth service – real-time, audio + video, FQ (audio-only telehealth when the provider is an FQHC (Federally Qualified Health Center) or RHC (Rural Health Clinic), and FR (used when billing for telehealth services furnished by remote or distant site practitioners). In 2025, there are several evolving or new rules around telehealth billing that impact how and when these modifiers are used.
- Updated guidelines for global surgical packages: There are new payer-specific rules and clarifications to avoid overpayment for modifiers such as -24, -25, -57, and -79, de.
- Pay Close Attention to Operative Reports
When coding surgical procedures, always review the entire operative (OP) report, not just the procedure title. Code based on the post-operative diagnosis, as it provides the most accurate reflection of what was found and performed during surgery. The indications section is equally important—it explains the reason for the surgery, notes any existing global period, and may highlight factors that made the procedure more complex.
Avoid coding directly from the pre-operative diagnosis or procedure title alone, as these may not capture intraoperative findings or changes made during the procedure. Always confirm that the OP report matches the correct patient record, and query the physician if any details or documentation are unclear.
- Always Check NCCI edits
The National Correct Coding Initiative (NCCI), developed by CMS, promotes uniform coding practices and helps prevent improper payments for Medicare Part B claims. When reporting multiple codes, always check for NCCI edits, which evaluate code pairs to determine whether they can be billed together.
NCCI includes three main types of edits:
- Procedure-to-Procedure (PTP) Edits – Prevent payment when incorrect or mutually exclusive code combinations are reported.
- Medically Unlikely Edits (MUEs) – Identify claim lines that report an improbable number of units for a single service.
- Add-on Code Edits – Ensure that add-on codes are reported only with their approved primary procedures.
If an NCCI edit applies, one of the codes will typically be denied unless a valid modifier justifies separate reporting. Regularly reviewing NCCI edits helps ensure accurate coding, reduce denials, and maintain compliance.
- Conduct Internal Audits
Internal coding audits are one of the most effective ways to ensure coding accuracy, compliance, and revenue integrity. Regular audits help identify common errors, detect patterns of undercoding or overcoding, and confirm that documentation supports the reported codes.
In a value-based care environment, accurate coding is more important than ever. Internal coding audits ensure that claims accurately reflect patient complexity, comorbidities, and outcomes, which directly impacts quality reporting, risk adjustment, and reimbursement under value-based payment models. By reviewing a sample of claims periodically, coding teams can spot training needs, evaluate modifier usage, verify adherence to payer and CMS guidelines, and ensure that quality metrics are correctly captured.
Improving medical billing accuracy through coding best practices is easier when you have the right support.
Benefits of Professional Medical Coding Support
Adhering to ICD-10 coding guidelines and maintaining CPT coding accuracy is essential to ensure proper reimbursement, reduce claim denials, and support compliance with payer and CMS guidelines. Partnering with a companies that offers medical coding outsourcing services ensures access to experienced coders who work with the latest technologies and software to help physicians document their services correctly on claims. Outsourcing medical billing and coding to an expert allows healthcare providers to focus on delivering high-quality patient care while ensuring timely claim submission, accurate reimbursement, and maintaining a competitive edge.
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