Proper coding is necessary on Medicare claims because codes are generally used to assist in determining coverage and payment amounts.
The CMS accepts only ICD-9-CM diagnostic and procedural codes that use definitions contained in DHHS Publication No. (PHS) 89-1260 or CMS approved errata and supplements to this publication. The CMS approves only changes issued by the Federal ICD-9-CM Coordination and Maintenance Committee. Diagnosis codes must be full ICD-9-CM diagnoses codes, including all five digits where applicable.
Diagnosis coding changes for Volume 1 and 2 are approved annually by a Federal committee. The changes take effect each year October 1. Volume 3 is revised annually by CMS. Updates include:
• Addition of new codes;
• Deletion of old codes; and
• Revisions to descriptions of codes.
• Deletion of old codes; and
• Revisions to descriptions of codes.
Rules for reporting diagnosis codes on the claim are:
• Use the ICD-9-CM code that describes the patient’s diagnosis, symptom, complaint, condition or problem. Do not code suspected diagnosis.
• Use the ICD-9-CM code that is chiefly responsible for the item or service provided.
• Assign codes to the highest level of specificity. Use the fourth and fifth digits where applicable.
• Use the ICD-9-CM code that is chiefly responsible for the item or service provided.
• Assign codes to the highest level of specificity. Use the fourth and fifth digits where applicable.
• Code a chronic condition as often as applicable to the patient’s treatment.
• Code all documented conditions that coexist at the time of the visit that require or affect patient care or treatment. (Do not code conditions that no longer exist.)
• Code all documented conditions that coexist at the time of the visit that require or affect patient care or treatment. (Do not code conditions that no longer exist.)
Claims submitted to the carrier on Form CMS-1500 or its electronic equivalent must have a diagnosis code to identify the patient’s diagnosis/condition (item 21). All physician and nonphysician specialties (e.g., PA, NP, CNS, CRNA) must use an ICD-9-CM code number and code to the highest level of specificity. Up to four codes may be submitted in priority order (primary, secondary condition). An independent laboratory is required to enter a diagnosis only for limited coverage procedures.
Inpatient claims submitted to the intermediary on Form CMS-1450 or its electronic equivalent must have a principal diagnosis. For inpatient claims, the provider reports the principal diagnosis in the appropriate form locator. The principal diagnosis is the condition established after study to be chiefly responsible for the admission. Even though another diagnosis may be more severe than the principal diagnosis, the principal diagnosis, as defined above, is entered. Entering any other diagnosis may result in incorrect assignment of a DRG and an overpayment to a hospital under PPS.
The physician should code the ICD-9-CM code that provides the highest degree of accuracy and completeness. In the context of ICD-9-CM coding, the “highest degree of specificity” refers to assigning the most precise ICD-9-CM code that most fully explains the narrative description of the symptom or diagnosis. Concerning level of specificity, ICD-9-CM codes contain either 3, 4, or 5-digits. If a 3-digit code has 4-digit codes which further describe it, then the 3-digit code is not acceptable for claim submission. If a 4-digit code has 5-digit codes which further describe it, then the 4-digit code is not acceptable for claim submission.
For electronically submitted DMEPOS claims, a valid diagnosis code, which most fully explains the patient’s diagnosis, is required. The CMS understands that physicians may not always provide suppliers of DMEPOS with the most specific diagnosis code, and may provide only a narrative description. In those cases, suppliers may choose to utilize a variety of sources to determine the most specific diagnosis code to include on the individual line items of the claim. These sources may include, but are not limited to: coding books and resources, contact with physicians or other health professionals, documentation contained in the patient’s medical record, or verbally from the patient’s physician or other healthcare professional.
For outpatient claims, providers report the full ICD-9-CM code for the diagnosis shown to be chiefly responsible for the outpatient services in the appropriate FL. For instance, if a patient is seen on an outpatient basis for an evaluation of a symptom (e.g., cough) for which a definitive diagnosis is not made, the symptom is reported (786.2). If, during the course of the outpatient evaluation and treatment, a definitive diagnosis is made (e.g., acute bronchitis), the definitive diagnosis is reported (466.0).
