Linking diagnoses and procedures to documentation in outpatient settings

by Lori-Lynne A. Webb, CPC, CCS-P, CCP, CHDA, COBGC, CDIP

In the outpatient setting, we have a different set of rules to follow in regard to the ICD-10-CM Official Guidelines for Coding and Reporting compared to those that follow the guidelines for inpatient care. The ICD-10-CM guidelines for outpatient coding are used by hospitals and providers for coding and reporting hospital-based outpatient services and provider-based office visits.

Following the guidelines

In addition, the terms "encounter" and "visit" can be used interchangeably. As a reminder, the guidelines for outpatient coding are different from inpatient coding because the term "principal diagnosis" is only applicable to inpatient services, as is coding diagnoses as probable, suspected, ruled out, and inconclusive.

For those who report outpatient or office-based services, instead of reporting a principal diagnosis, you would code the first-listed diagnosis, as well as signs and symptoms that are documented by the provider of care. In some cases, it may take more than one visit or encounter to arrive at and/or confirm a specific diagnosis. ICD-10-CM guidelines allow us to continue to report signs and symptoms over the course of the outpatient workup. The majority of the sign and symptom codes are found in Chapter 18 of ICD-10-CM; however, other sign and symptom codes can be found in many of the other sections and chapters of ICD-10-CM.

When assigning an ICD-10-CM diagnosis code for an outpatient or same-day surgery, it is appropriate to code the reason for the surgery as the first-listed diagnosis (i.e., reason for the encounter). When coding for an outpatient hospital observation stay, it is appropriate to code the current medical condition as the first-listed diagnosis (e.g., pregnant patient with decreased fetal movement).

In addition, it is appropriate to code for all additionally documented conditions. If the patient has chronic diseases noted, the chronic disease or disease status may be coded in addition to the primary reason the patient is seeking treatment, but only if the physician documents the chronic condition as impacting the current care or medical decision-making of the presenting problem or illness.

Dealing with documentation

Diagnosis codes are to be used and reported at the highest possible number of characters and specificity. However, sometimes all we have to go by is provider documentation of signs and symptoms. If the provider has not referenced a clinical significance to complaints or has only documented ill-defined symptoms, we have to code the documentation as a sign or symptom from the ICD-10-CM code set. It is the provider’s responsibility to clearly document a patient’s diagnosis.

Coders are not allowed to infer or code directly from an impression on diagnostic reports such as an x-ray, ultrasound, or pathology report. In the outpatient setting, the provider of care must confirm the diagnosis in the body of the patient’s visit note, procedure/operative note, or progress note.

For example, in the provider notes, the documentation states the patient has an "elevated blood pressure" of 160/90. As a coder, this does not mean the provider has diagnosed the patient with hypertension; it simply means the patient’s blood pressure is elevated today. However, if the provider notes that the patient has an elevated blood pressure of 160/90 today and will begin treatment for hypertension, the coder can code the ­specific hypertension diagnosis rather than the sign and symptom code of elevated blood pressure. If the coder does not have more specific information than "hypertension" written in the record, he or she should query the provider to get the most clarity possible, ensuring good clinical documentation and overall quality of medical care.

When assigning codes for an outpatient or ambulatory surgery case, code the diagnosis for which the surgery was performed. However, if the postoperative diagnosis is different than the preoperative diagnosis listed by the surgeon, code what is reported as the postoperative diagnosis. In reviewing or auditing an operative record, the surgeon should give both diagnoses. The rule of thumb is that the coder will code the diagnosis based on the postoperative notation or most definitive clinical documentation recorded in the patient’s medical chart.

When coding a diagnosis for ambulatory or same-day surgery, the urge to rely on the absolute information from a pathology report can be hard to resist. As coders, we have been trained to hold or delay submitting the insurance claim pending more information from a pathology report. Pathology reports contain great information on sizes, weights, measurements, cell types, malignancies, infections; they can house even more extensive clinical information than is normally reported in an operative/procedure record.

However, within the guidelines of coding, coders should not assign codes based on the pathology report unless the physician has confirmed the diagnosis within the operative, procedure, or progress notes. For example, if the physician notes within the documentation the removal of a "breast lesion/mass" and the pathology record documentation states "breast carcinoma," the coder should not code a breast carcinoma until the surgeon clarifies or adds the information from the pathology report to the operative and/or progress note.

Pathology reports can help us paint the picture of a patient’s status, but they can also be a hindrance. When coding for a lesion removal with CPT® codes, understanding how lesions are measured is vital to good documentation of the procedure. According to the CPT Manual, the measurements of the lesion need to include the size of the lesion itself and the margins for medical necessity prior to excision.

As part of good clinical documentation, the provider should document and include an accurate measurement of the lesion itself, and of the margins to be included. If the coder relies on only the pathology report, the sizing may not be accurate. Unfortunately, when excising specimens, it is common for the procured tissue to shrink or the specimen to be fragmented upon arriving at the pathology department. Measurement of the defect size post-excision may also be incorrect, as the excision site may expand once the tissue has been incised or excised. Either way, the result is incorrect documentation and coding.

The documentation bottom line is this:

• Measurement of the lesion, plus the margins, should be made prior to the excision
• Pathology reports should not be used in lieu of physician documentation
• Query the physician regarding the size of the lesion, as well as the margins, excised if not clearly noted in the operative/procedure note

Using queries

Below is a generic lesion excision query form you can use to communicate to your provider the information you need to accurately code the encounter.

Excision of lesion(s) clarification

• Patient name:
• DOB:
• DOS:
• MR #:
• Query date:
• Requested by:

Documentation clarification is required to meet medical record documentation compliance, medical necessity, and accuracy of diagnosis and procedure coding.

In the medical record/operative procedure note, the following information is needed to assign the correct ICD-10-CM and CPT code(s). Please provide the following:

• SIZE of the greatest clinical diameter in centimeters plus margins for each lesion excised
• DEPTH of the tissue involved for each lesion (e.g., skin, fascia, muscle, or bone)
• Type of CLOSURE for each lesion (e.g., simple, intermediate, or complex)

Please document and/or addend the patient’s operative/procedure record to include the requested information above. This information can be noted in the electronic medical record, or noted on this form in the area below. If you are using this form, please sign and date the attestation/addendum.

Following a checklist

The relationship between documentation and coding is intricate and often confusing. Every chart note, or piece of clinical documentation in the record, must stand on its own merit. If the record is audited, the coding should accurately reflect what was noted by the provider.

The documentation should always clearly reflect the following criteria:

• Clinical evaluation and workup, including any pertinent history
• Diagnostic and/or therapeutic treatment(s) carried out or ordered (e.g., lab tests, x-rays)
• Continued plan of care or follow-up plans
• Clinical diagnosis of disease, signs, and/or symptoms
• Documentation of patient education provided in regard to the above

Electronic medical records for outpatient care and office-based services have also been instrumental in giving coders a clearer picture of the overall care and services provided to patients. Many electronic medical records allow the physician to choose the ICD-10-CM diagnosis code and include the additional supplies or procedures performed during the visit. If the provider documents a diagnosis for any performed procedures via an electronic record, the coder now has the additional role of auditing the patient record and the actual diagnosis codes chosen by the provider prior to billing the third-party insurance payers.

If upon review the coder (or auditor) sees the physician or provider has not chosen the most specific codes, the coder can easily review, clarify, and/or correct any errors quickly and easily prior to a claim being sent out. In addition, some payers have the capability to accept electronic copies of patients’ clinical documentation for their review or pre-authorization to expedite payment of services rendered.

Outpatient and office-based services are not always about illness. Wellness services, preventive care, pre- and postoperative care, and specialty-specific diagnosis care are all part of outpatient and office-based services. ICD-10-CM has accounted for these encounter types. If these encounters are well documented, they also need to be coded, billed, and incorporated into the claim. Many third-party payers are now providing coverage for payment of screening services.

The ICD-10-CM coding guidelines give clear instruction for how these types of services are to be reported. Again, it is the physician’s role to clearly state within the clinical documentation that the patient has presented for a wellness exam or a screening for specific illnesses or diagnoses (e.g., a pap test for cervical cancer, a colonoscopy to screen for colon cancer, lab tests for elevated blood sugar/diabetes). In these cases, the coding should reflect a clear diagnosis of screening. The screening diagnosis may be the only diagnosis assigned, as it may be the only reason for the patient visit.

It is becoming more common for physicians to follow and provide care for an established chronic problem while also screening for other issues during the encounter for that problem. If this is the case, the coder needs to audit and review the notes carefully to ensure the record clearly denotes what has been performed as follow-up care and what has been performed as screening (for either wellness or a suspected illness). If the record does not clearly show these as separately identifiable services, a physician query and/or addendum is in order.

Last but not least, always code what the record shows. If in doubt, query. Many coders rely on the old adage of "if it wasn’t documented, it wasn’t done." This type of coding should no longer be the rule of thumb or status quo. If a service or procedure appears in the clinical documentation but is poorly documented, good coders will find it well worth their time to investigate, confirm, have the record amended, and then code with accuracy. 

Editor’s note

Webb is an E/M and procedure-based coding, compliance, data charge entry, and HIPAA privacy specialist with more than 20 years of experience. Her coding specialty is OB/GYN office/hospitalist services, maternal fetal medicine, OB/GYN oncology, urology, and general surgical coding. She can be reached via email at [email protected] or http://lori-lynnescodingcoachblog.blogspot.com. Opinions expressed are that of the author and do not represent HCPro or ACDIS.

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