Effectively navigating ICD-10 coding is paramount for maintaining excellent patient care, ensuring accurate claim submissions, and safeguarding against potential payer audits—especially within ASCs. Incorrect diagnoses can lead to lasting consequences, affecting both patient records and reimbursement. While surgeons are ultimately responsible for code selection, collaboration among all involved parties is essential to resolve discrepancies and avoid future claim issues.
Understanding the downstream consequences of inaccurate coding is imperative. Payer audits often scrutinize the consistency between documented ICD-10 codes and submitted claims. Errors, such as incorrect laterality or unsupported medical necessity, can result in denied payments and financial repercussions. To avoid these issues, follow the steps below to ensure that the proper diagnosis codes are used.
1. Understand the Code Structure
ICD-10-CM codes can be three to seven characters long, with the potential for an alpha or numeric sixth or seventh character. A dash (-) at the end signals the need for additional characters. It is rare for a billable ICD-10-CM code to consist of only three digits. Codes specifying laterality—such as right, left, bilateral, or specific areas like right upper lid or left upper lid—must be fully specified to avoid claim denials, while some codes, like glaucoma staging codes, may necessitate additional characters indicating severity.
2. Verify, Then Trust
The codes that surgeons select affect both the surgeon’s and the ASC’s reimbursement. Therefore, it is crucial for the ASC to verify the accuracy of diagnosis and procedure codes before submission. For example, if a patient undergoes cataract surgery on the right eye, the ASC must ensure the diagnosis code aligns with the correct eye to prevent claim issues with the surgery for the right eye and potential future claim issues (cataract surgery in the left eye).
3. Utilize the Alphabetical Index
The Alphabetical Index is a valuable tool to identify specific diagnostic terms related to the surgical procedure. It is usually the first stop when trying to find a code and provides a comprehensive list of terms, aiding in precise code selection. For example, with cataract surgery, start by looking up “Cataract” in the Alphabetical Index to find the family of possible ICD-10 diagnosis codes (H25-H28). This comprehensive list catalogs thousands of main diagnostic terms alongside their corresponding ICD-10 codes. Each main term often branches into a sublist of more detailed terms.
4. Cross-Reference in the Tabular List
Once identified in the Alphabetical Index, cross-referencing the code in the Tabular List is crucial for accurate code selection. The Tabular List provides detailed information, including specific codes and guidelines for each condition. Organized alphanumerically from A00.0 to Z99.89, this list encompasses ICD-10 codes with detailed descriptors. The Tabular List is categorized into chapters based on body parts or conditions. While most ophthalmology codes reside in chapter 7 (Diseases of the Eye and Adnexa), exceptions like diabetic retinopathy codes are in chapter 4 (Endocrine, Nutritional, and Metabolic Diseases).1
Example: For the cataract procedure, locate the identified code in the relevant chapter of the Tabular List to ensure precision, considering factors like the approach and reason for the surgery.
5. Avoid Using “probable,” “suspected,” “possible,” “rule out,” or “unspecified” Codes
Code only confirmed diagnoses based on chart documentation. Refrain from coding when a definitive disease or problem has not been determined. Instead, focus on coding related to known details, such as signs, symptoms, complaints, or existing systemic diseases.
Coding to the highest level of specificity is a key principle for ICD-10 coding. Many codes that include laterality also include an option for unspecified eye (with a 9 as the digit), but it is never appropriate to use the unspecified eye option as this information should always be known. An ASC should never submit a cataract diagnosis of H25.819 (Combined forms of age-related cataract, unspecified eye), for example—the appropriate code would either be H25.811 for the right eye or H25.812 for the left eye.2
6. Deciphering Excludes Notes
Excludes1 notes indicate mutually exclusive ICD-10 diagnosis codes or conditions that cannot be reported together. A denial or recoupment after an audit can occur if two ICD-10 diagnosis codes that have Excludes1 notes are reported together. For example, H02.81 (Retained foreign body in eyelid) has an Excludes1 note, prohibiting billing with codes like S01.12- (Laceration of eyelid with foreign body) or H44.6- (Retained intraocular foreign body).
7. Effective Use of Placeholder ”X”
For certain codes, the addition of “X” serves as a placeholder for the future expansion of the codes and/or disease. Take, for example, the injury or trauma diagnosis codes in the Tabular List. Payers typically mandate the inclusion of a letter as the seventh character in these codes: A for an initial encounter, D for a subsequent encounter, or S for sequela. In cases where these codes consist of only five characters, an X functions as a placeholder in the sixth position.
As an example, for a surgical patient requiring additional surgery due to complications from a burn to the left eyelid and periocular area, the appropriate ICD-10 code is T26.02 for “Burn of left eyelid and periocular area.” To indicate the current condition is a sequela of a previously known injury, add S as the seventh character. As it is a five-character code, employ X as a placeholder—resulting in T26.02XS.
For a diagnosis of primary open-angle glaucoma, severe stage, in the right eye, the appropriate code is H40.11X3. Unlike some glaucoma codes necessitating laterality indication in the sixth character, H40.11 doesn’t require it. However, staging must be specified with the seventh character, for which the coder should utilize “X” as a placeholder.
8. Interpret “and/or”
Decoding conjunctions like “and” in titles (such as H26.0 for infantile and juvenile cataract) is significant for surgical cases, as it indicates both and/or scenarios. Understanding nuances in titles ensures accurate representation of the patient’s diagnosis.
9. Align ASC Facility Coding with the Surgeon’s Coding
Harmony between ASC facility coding and surgeon’s coding is integral. Failure to tell the same story to the payer through the correct and consistent submission of ICD-10 codes is telling the payer that either the surgeon or the facility is not right. Foster open communication, implement shared training programs, conduct cross-audits, utilize common resources, establish a collaborative review process, define clear documentation protocols, and provide continuous education for coding staff.
For example, a physician submits a combined cataract/MIGS procedure listing the cataract diagnosis as the primary diagnosis and the glaucoma diagnosis as the secondary diagnosis. The surgeon is reimbursed for the procedure. The ASC submits a combined cataract/MIGS procedure listing the glaucoma diagnosis as primary and the cataract diagnosis secondary. The claim is denied. This example also highlights the first rule of coding and billing: identify the payer and their published policies.
10. Implement Regular Internal Audits
Establish a routine internal audit process to review coding practices, identify potential errors, and ensure compliance with coding guidelines. Conducting periodic internal audits allows for the identification and correction of coding errors, minimizes the likelihood of claim denials, and supports a culture of continuous improvement. OASC
References
1. Vicchrilli S. ICD-10: How to Find the Correct Code in 5 Steps. Eyenet. March 2015. Accessed March 18, 2024. https://www.aao.org/eyenet/article/icd-10-how-to-find-correct-code-in-5-steps
2. American Academy of Ophthalmology. Focus on the Fundamentals: ICD-10-CM Coding Principles. January 23, 2024. Accessed March 18, 2024. https://www.aao.org/practice-management/news-detail/focus-on-fundamentals-icd-10-cm-coding-principles
