Complete Story


Diagnoses Coding 101… and Your Practice


Diane E. Zucker, M.Ed., CCS-P
Health Care Management Consultant

Diagnoses coding as evolved over the years since the implementation of ICD 10 in 2015. The details it presented can be overwhelming. The coding by specific location of a condition, the specificity of the disease and the status or stage seemed a daunting task to document and code. The need to update an ICD 10 code based on the status at each given encounter was frustrating. This process combined with the various EMR’s that made (and make) adding a diagnoses or updating an existing problem an onerous activity. Many EMR “problem” lists create a false sense of security about the coding as they automatically import information without clear validation or accuracy create.


In moving to 2021 and the E/M changes for levels of care including simplification of how documentation of history and exam relies heavily on accurate primary diagnoses addressed in your encounter, pertinent secondary issues that impact your plan and in some cases additional psycho-social factors that may complicate patient care.


The level of E/M coding for outpatient/office services in 2021 is based on the nature and acuity of the problem—reflected in the diagnosis’s narrative. Is the problem acute or chronic? It the problem stable or unstable? Are there issues with medication or intervention? What are the long term risks for vision loss or blindness? And are their secondary issues with medical concerns altering your care plan, testing you perform or order and frequency of visits. And the addition of a new process of “psycho-social determinants of health adds even more ICD 10 codes to the mix. The data that is now part of the E/M calculation process requires supporting documentation often of diagnoses or status when coding higher levels care. Surveillance coding (Z09) after completion of some types of care may be included with the specific diagnosis. The scans and technology unique to ophthalmology may need to be explained to a third party with more than just one code (high risk medication, medical condition complicating care, or psycho-social determinants of health issues).


All these codes can often frustrate and confuse the practitioners and support staff.  Why do new need to update the glaucoma or the macular codes? How important is this to the visit? And can’t we just change it when the claim is denied, or prior authorization is required?  This process can be complicated to learn and adapt to your practice but remember that the coding you do reflects the care provided and needs to be accurately reflected when care is provided and submitted for payment—so “back coding” is not an option!


The energy to reflect the correct primary and secondary diagnoses and status will support that higher level acuity. The needed second or third diagnoses will support not only the higher level coding but also the additional scan or imaging required for a complete diagnosis or monitoring of a case. That second diagnoses may also help support the use of modifier -25 when two or more services are provided on the same day. 


With the changes in E/M documentation and coding for office services in 2021 and the focus on quality reporting diagnoses coding has taken on critical role within the documentation of care and the assignment of the specific ICD 10 code. The days of looking at diagnoses coding for just payment of a service are over as now this process is not just about the claim today but links to frequency of services; future testing or visits; and quality improvement which can support bonus payments. Good diagnoses coding provides many other benefits to practices including reduced denials, reduced claim review and audits and ease in meeting patient care needs with services that require prior authorization or post pay review.


As we think about the overall process for diagnoses coding it is not just about payment but about care….


First all ICD 10 coding is based on the documentation which may be part of an E/M service and the associated testing that may specify the condition.  The specific eye of the condition is always required as it the specific degree of a condition (glaucoma, macular degeneration).  Is the condition acute or chronic?  If the condition is chronic, one that will be with the patient at least a year or until death, then the specific status of the condition should be reflected and coded appropriate. An unspecified diagnoses may be appropriate at an initial assessment and during the work up phase of care.   So blurred vision or dry eye of uncertain source could be coded as unspecified or uncertain behavior. 


Conditions change in terms of progression, deterioration or improvement with intervention.  With this identified one cannot rely on a set problem list or the diagnoses from the prior visit or prior testing.  This process needs to be validated and updated at each and every encounter.  So as the patient is seen at each visit the specific eye, the specific level of the condition needs to be reflected as part of the assessment and then coded accordingly.  This coding process then helps support the status of the condition as required in E/M coding for 2021.  


In cases where the reason for care is to monitor the eye status because of a systemic condition like lupus, multiple sclerosis, hypertension,  or rheumatoid arthritis, these conditions would be coded and as pertinent to care the diagnoses for the high- risk medication that impacts the treatment of these conditions would also be coded.


If there is an acute eye injury or eye condition (conjunctivitis) this may not be a higher level of acuity for E/M coding but if there are secondary issues that impact the decision making then the coding of this information supports the care provided.    A couple examples would be the foreign body in the eye that provides you the opportunity to educate the patient about risks of chronic conditions base on a family history of conditions that impact vision.  The person that comes in with an acute conjunctivitis that is recurrent in nature may expand your assessment to other related issues that complicate the care you provided.  This may include addition facts like they are a swimmer or perhaps a referral for an allergy assessment.


The role of secondary conditions addressed within each visit also provide an opportunity to reflect the specific ICD 10 code that impacts the overall care plan.  The diagnoses is not a set process but fluid that changes based on the specific circumstances at the visit.   The ophthalmologist may be involved in care not just because of the vision issues but to assess how chronic conditions like diabetes, hypertension, renal failure, lupus to identify a few.  In early phases of a chronic condition vision may not be impacted at the level the patient “knows” but you the ophthalmologist can identify before the issues become debilitating.


As quality improvement measures are reviewed and performed the ICD 10 codes need to correspond with this process.  Those beyond vision and eye care may require specific ICD 10 codes.  Smoking that complicates overall vision and eye care would be ICD 10 coded with the F17.288 or other specific tobacco dependence code.  


Patients who are identified as talking high risk medication that impacts vision care would have this validated and if this is pertinent to the care.  If these drugs are compromising vision or eye pressure the T code for the drug as an adverse reaction may be coded.  This coding of the correct ICD 10 code would then reflect in higher E/M coding.  A great example would be steroids and glaucoma.


The monitoring of refractive issues alone are a part of your diagnoses coding but in cases where the secondary issues lurk without current impact, still require monitoring and ongoing review and education.  This awareness of other concerns may not result in an ICD 10 code for today’s visit but in a future visit may be warranted. An example would be a child or adolescent who has failed a vision screen at school that does not have a vision loss but during your assessment you identify a positive family history of risk or hobbies (swimming) or occupation (exposure to chemicals) that would support education and awareness for eye health. That 14 year old that works on model cars or the avid cyclist would be educated about protective eye gear.


The other things that are “out there” that may need to be coded to explain your referrals, monitoring process, testing (or lack of it) can be coded. The patient who cannot afford the best eye wear and is referred to a vision support program would have financial hardship. The noncompliance that impacts long term eye health might need to be coded. Or the patient whose family dysfunction has resulted in the lost contacts, medication, or glasses for the 3rd time in a year may end up with the family dysfunction ICD 10 code Z63.8 or the patient who has lost a house to fire and needs all medication refilled  with Z63.79 (stressful household events). When you think about your elderly patients after surgery, additional accommodations (home health) may be required if they live alone (Z60.2)


Now that you are completely overwhelmed with what can have an ICD 10 code assigned let’s review the particle side for your documentation of these issues.

  1. You can have up to twelve ICD 10 codes on a claim form. They should be rank ordered based on what you are managing and addressing in your note.

  2. The problem list in the EMR may not be these diagnoses – as you are only identifying the ICD 10 codes that impact the care you provide (not the hernia from 2010).

  3. As you create the visit today you may need 3 distinct diagnoses – the primary one specific to what you are seeing, any secondary one(s) that change your care plan (diabetes or COPD on steroids) and that psycho-social determinant of health that changes your care plan.

The support staff, techs, billers, and coders can help with this process but you the physician do need to actively engage and take the leadership role in diagnoses coding to assure your care is accurately documented, correctly billed and paid.

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