To Code or Not To Code

Tune in to this monthly online coding column, facilitated by AHIMA’s coding experts, to learn about challenging areas and documentation opportunities for ICD-10-CM/PCS.

By Elena Miller, MPH, RHIA, CCS


The Centers for Medicare and Medicaid Services’ Risk Adjustment model is not new. However, Hierarchical Condition Categories (HCCs) seem to be this year’s buzz word. Vendors are offering training courses to educate on HCCs, specialized risk adjustment coding credentials have been created, and lots of conversations are taking place about chronic conditions and how they impact reimbursement. There’s just one thing that isn’t being said enough: just because it’s documented doesn’t mean that it should be coded. There are coding guidelines that must be applied.

Historically, there hasn’t been a lot of pressure on outpatient or physician coders as it relates to secondary diagnosis code assignment. That is no longer the case. I’ve heard HCCs described as the outpatient equivalent to MCCs and CCs. Now more than ever, outpatient and physician coders are being questioned about accurately applying the secondary diagnosis codes.

There is good news. The coding guidelines related to secondary diagnosis code assignment are very clear and have been constant over the years. Outpatient code assignment should be based on Section I of the coding guidelines which is applicable to all healthcare settings and Section IV which is specific to outpatient services (including provider-based office visits).

Section IV of the coding guidelines has two components that help to direct decisions regarding secondary diagnosis code assignment.

  • Chronic diseases treated on an ongoing basis may be coded and reported as many times as the patient receives treatment and care for the condition(s)
  • Code all documented conditions that coexist at the time of the encounter/visit, and require or affect patient care treatment or management. Do not code conditions that were previously treated and no longer exist. However, history codes (categories Z80-Z87) may be used as secondary codes if the historical condition or family history has an impact on current care or influences treatment.

The rules are straightforward, the difficulty in code assignment comes from the limited documentation available to outpatient and physician coders. The patients are there for a limited time and there just isn’t much documentation to work with. Outpatient coders should ask themselves a series of questions prior to assigning a secondary diagnosis code.

  1. Does the condition currently exist? Some physicians include resolved conditions in their documentation. For example, a patient is being seen in the emergency department for chest pain. The physician may note that the patient completed treatment for a UTI three weeks ago. The patient’s symptoms have resolved and the physician is not evaluating the condition. This is a notation of a resolved condition; it should not be assigned as an additional code.
  2. Is this a current condition, that is being treated or affecting the patient care/management? Same patient as the scenario above. This time, the physician notes that the patient completed antibiotics for a UTI but is still experiencing dysuria. The physician orders a urinalysis and gives the patient another prescription of antibiotics for treatment of the UTI. In this case, the condition is documented as current and is being actively treated. An additional code should be assigned.
  3. Is this a chronic condition, in which the patient receives ongoing treatment/care? The patient presents for a well-visit; the physician evaluates the patient for ongoing issues with hypertension and diabetes. According to the American Hospital Association’s Coding Clinic from the third quarter of 2007, chronic conditions such as, but not limited to, hypertension, Parkinson’s disease, COPD, and diabetes mellitus are chronic systemic diseases that ordinarily should be coded even in the absence of documented intervention or further evaluation. In this scenario, hypertension and diabetes should be assigned as secondary diagnoses.
  4. Does this history or status have an impact on current care? Facilities may have internal policies in place regarding history/status codes that should be followed. Generally, these codes should only be assigned if they are pertinent to the case.

Just remember that HCCs do not come with their own coding rules, neither do they change the existing coding rules. Let your code assignment be driven by applying index instruction, coding guidelines, and Coding Clinic to the documentation to result in consistent coding across the board. Coders should be focused on accuracy. You can’t go wrong with quality coding…


Elena Miller is the director of coding audit and education at a healthcare system.


  1. Have HCC guidelines been updated as CC have on assumed relation between hypertension and CHF or diabetes and other associated conditions?

    Post a Reply
    • Yes they are the same and they are called coding guidelines not HCC or CC guidelines

      Post a Reply
  2. My question is does anyone have a list of what all is considered a chronic condition? What do follow to look up and determine if a disease is considered chronic? Thanks

    Post a Reply
  3. Risk Adjustment and Hierarchical Condition Category (HCC) coding is a payment model mandated by the Centers for Medicare and Medicaid Services (CMS) in 1997. Implemented in 2003, this model identifies individuals with serious or chronic illness and assigns a risk factor score to the person based upon a combination of the individual’s health conditions and demographic details. The individual’s health conditions are identified via International Classification of Diseases – 10 (ICD –10) diagnoses that are submitted by providers on incoming claims. There are more than 9000 ICD-10 codes that map to 79 HCC codes in the Risk Adjustment model. The original goal of HCCs was to ensure that money could be earmarked to cover a patient’s future medical needs. This model has been the basis for CMS to reimburse Medicare Advantage (MA) plans (Medicare Part C) based on the health of its members.

    Post a Reply
  4. Hello,

    In HCC, should all active conditions be moved to problem list from PMH?

    Post a Reply
  5. Are HCC just coded from only an outpatient encounter? I am an Inpatient coder and our CDI department queries physicians based on previous encounters not just the current Inpatient encounter as our AHIMA coding ehtics states coders should only query from current encounter. Please advise.

    Post a Reply
    • From what I understand, HCC’s will look across all episodes of care across the defined span of time regardless of the setting. This means that codes picked up on an inpatient stay will be included in the longitudinal analysis of HCCs for a patient.

      However, coding should follow the guidance of diagnoses pertinent to the encounter being coded. The diagnosis may have been historical but impacted decision-making in current care. I would not think it would be appropriate to review prior visits to query for non-provider documented or indicated conditions.

      Post a Reply
    • Acceptable sources for Risk Adjustment coding are Professional visits (physician office and hospital visits), inpatient stays and outpatient encounters. Data from alternative care settings such as Rehab Facilities cannot be used. It is an accepted coding practice and one that arises from Medicare policy that each episode of care must stand on its own merit with regards to coding. Prior to discontinuance of the Physician Attestation Statement, and when we were all on paper records, it was accepted practice to look at previous admissions for clarity on diagnosis code assignment (Type I versus Type II Diabetes specificity as one example). That is no longer the case. Each encounter must stand on its own merit and therefore the documentation in that encounter must support the codes that are assigned for the encounter. The Official Guidelines for Coding and Reporting (OGCR) are clear on this – look for the guidance on the capture of secondary diagnosis codes.

      Post a Reply
  6. Regarding diabetes, in HCC we code this as chronic, do we have to code glaucoma or skin ulcer that are related to diabetes?

    Post a Reply
  7. Why are people coding HCC’s on OP encounters? HCC’s are a risk adjusted payment model required of Medicare Advantage plans to pre-determine a patient’s potential need for dollars based on their diagnoses. Coders should NOT be coding for HCC’s… they should only report confirmed diagnoses documented by the QHP. Period. It is the payer’s job to “sift through” the chart to determine what HCC’s come in to play. Why are coders trying to code HCC’s??? What is going on here?

    Post a Reply
    • @ Stephen – Many of us here know this already, but your response includes incorrect information. HCC coding (AKA Risk Adjustment Coding) is done for Inpatient as well as Outpatient/Physician and certain Specialty Provider services. Some of us are HCC Coders and are assigned to projects where we basically only code HCC’s. We even have a credential for it (CRC – with AAPC).

      Post a Reply
  8. When coding HCC and the patient is being seen for office visit or assessment, do you also use the Z0 codes also? We have an auditor stating we are not to use codes like Z01.89, Z76.89 at the end of each assessment or visit. We include all the HCC’s so is this accurate. Thanks!

    Post a Reply
  9. The guidance in the article referring to the 2007 CC re: coding chronic conditions only applies to inpatient, not outpatient. Coding guidelines for reporting chronic conditions is not superseded by whether or not there is a HCC vs a non-HCC and just to get paid. It will ALWAYS come down to documentation. I’m a CCS not a CPC, and have always coded for a facility and not on the pro-fee side. Just because a lot of payers are now looking for those HCC’s does not mean we as coders should just accept it and start reporting them… this sounds to me like a huge disaster waiting to happen.

    Post a Reply

Submit a Comment

Your email address will not be published. Required fields are marked *

Share This

Share This

Share this post with your friends!