CDI Documentation Tips for Experienced Hospitalists for 2021

“ICD-10-CM Official Guidelines for Coding and Reporting” is released every year and these guidelines are valid from October 1st of one year to September 30th of the next year.

After going through all the 126 pages from the latest guidelines, here are some key takeaways that are useful to the hospitalists in documentation.

These are useful for those who want to be Physician Advisors in CDI.

Body Mass Index (BMI), depth of non-pressure chronic ulcers, pressure ulcer stage, coma scale, and NIH stroke scale (NIHSS) can be coded from the documentation done by those who are not doctors since this information is typically documented by e.g., a dietitian often documents the BMI, a nurse often documents the pressure ulcer stages, and an emergency medical technician often documents the coma scale. However, the Doctors have to document associated diagnosis (such as overweight, obesity, acute stroke, or pressure ulcer) or else that info from others like RN, Dietician, etc can’t be coded.

If a definitive diagnosis is not established by the time of discharge for any patient, sign(s) and/or symptom(s) can be coded in lieu of a definitive diagnosis. Otherwise, avoid signs and symptoms and document only the diagnoses in assessment and plan.

For COVID-19 infection (infection due to SARS-CoV-2), only confirmed cases are coded. Confirmation does not require documentation of a positive test result for COVID-19. The doctor’s documentation that the individual has COVID-19 is sufficient. If the doctor documents “suspected,” “possible,” “probable,” or “inconclusive”, then only the signs and symptoms are coded and not COVID 19. This is an exception to the usual rule that “Suspected” diagnoses are coded as Confirmed in other situations.

The principal diagnosis is defined in the Uniform Hospital Discharge Data Set (UHDDS) as “that condition established after study to be chiefly responsible for occasioning the admission of the patient to the hospital for care.”

If the patient has Acute respiratory or non-respiratory manifestations of COVID-19 at the time of admission like Pneumonia, Acute bronchitis, Acute respiratory distress syndrome, Acute respiratory failure or viral enteritis, COVID-19 is still the principal diagnosis and not those respiratory or GI complications/manifestations.

During pregnancy, childbirth or the puerperium, when COVID-19 is the reason for admission, code O98.5-, Other viral diseases complicating pregnancy, childbirth and the puerperium is the principal diagnosis, and code U07.1, COVID-19 will be a secondary diagnosis unlike above point. Here Pregnancy takes precedence over COVID as per the rule.

When admission is for management of an anemia associated with the malignancy, and the treatment is only for anemia, malignancy is the principal diagnosis followed by the appropriate code D63.0, Anemia in neoplastic disease as secondary diagnosis.

If the patient is treated with both PO medications and insulin for diabetes, only long-term (current) use of insulin is coded. If the patient is treated with both insulin and an injectable non-insulin antidiabetic drug, Long-term (current) use of insulin, and Z79.899, Other long term (current) drug therapy are coded. If the patient is treated with both oral hypoglycemic drugs and an injectable non-insulin antidiabetic drug, Z79.84, Long-term (current) use of oral hypoglycemic drugs, and Z79.899, Other long-term (current) drug therapy are coded.

When the documentation refers to use, abuse and dependence of the same substance (e.g. alcohol, opioid, cannabis, etc.), only one of those diagnoses is coded in this order: Dependence >Abuse>Use. So, writing both Abuse and Dependence is not needed, just Dependence is enough.

When a patient has CVA, should the affected side be documented, but not specified as dominant or nondominant, then for ambidextrous patients, the default should be dominant for either right or left.  If the left side is affected, the default is non-dominant. If the right side is affected, the default is dominant.

Patient with encounter for pain management for acute neck pain from trauma, code G89.11, Acute pain due to trauma is the principal diagnosis, followed by code M54.2, Cervicalgia as secondary diagnosis.

The classification presumes a causal relationship between hypertension and heart involvement and between hypertension and kidney involvement, as the two conditions. [Same way Diabetes and Peripheral Neuropathy]. These conditions will be coded as related even in the absence of doctor documentation explicitly linking them, unless the documentation states these conditions are unrelated.

If the patient does not have an established diagnosis of hypertension, but now has Hypertension temporarily due to some condition, it will be coded as code R03.0, Elevated blood pressure reading without diagnosis of hypertension.

We all know that Hypertensive crisis is either Hypertensive Urgency or Hypertensive Emergency. Uncontrolled hypertension may refer to untreated hypertension or hypertension not responding to current therapeutic regimen. This can be useful if BP does not meet criteria for Hypertensive Crisis.

If a type 1 NSTEMI evolves to STEMI, it will be assigned the STEMI code. If a type 1 STEMI gets converted to NSTEMI due to thrombolytic therapy, it will still be coded as STEMI.

Question: A patient admitted to the ED with acute respiratory failure and aspiration pneumonia due to overdose of a narcotic. What is the Principal Diagnosis? If you thought that Acute respiratory failure is the principal diagnosis, please read the below official coding guideline from ICD 10.

Acute respiratory failure, Acute and chronic respiratory failure, may be assigned as a principal diagnosis when it is the condition established after study to be chiefly responsible for occasioning the admission to the hospital. However, chapter specific coding guidelines from ICD 10 rules give priority to conditions such as obstetrics, poisoning, HIV, newborn . In the above question, “Poisoning related to Medication” is the Principal Diagnosis and not acute respiratory failure.

For patients presenting with condition(s) related to vaping, the principal diagnosis is U07.0, Vaping-related disorder. Other manifestations, such as acute respiratory failure (subcategory J96.0-) or pneumonitis (code J68.0) are secondary diagnoses.

Unstageable pressure ulcers are those pressure ulcers whose stage cannot be determined when the ulcers are covered by an eschar or they been treated with a skin or muscle graft.

If a patient is admitted to the hospital with a pressure ulcer at one stage and it later progresses to a higher stage, two separate codes should be assigned: one code for the site and stage of the ulcer on admission and a second code for the same ulcer site and the highest stage reported during the hospital stay.

If both CKD and ESRD are documented for a patient’s disease of the kidneys, ESRD will only be coded.

It is coded as a transplant complication only if the complication affects the function of the transplanted organ. Patients who have undergone kidney transplant may still have some form of chronic kidney disease (CKD) because the kidney transplant may not fully restore kidney function. Therefore, the presence of CKD alone does not constitute a transplant complication.

The systemic inflammatory response syndrome (SIRS) can develop as a result of certain non-infectious disease processes, such as trauma, malignant neoplasm, or pancreatitis.  In these cases, document SIRS with or without organ dysfunction as SIRS with or without organ dysfunction is coded as secondary diagnosis in these non-infectious SIRS cases.

Initial encounter is used for each encounter where the patient is receiving active treatment for the condition. You may be the fourth doctor seeing this patient during that admission but it is still initial encounter during active treatment phase.  Subsequent encounter is used for encounters after the patient has completed active treatment of the condition and is receiving routine care for the condition during the healing or recovery phase.

Please check out some tips regarding Open Progress Notes if you have not done yet. Open Progress Notes and Discharge summary; What hospitalists need to know

A fracture not indicated as open or closed will be coded to closed by default if not clearly documented. A fracture not indicated whether displaced or not displaced will be coded as displaced by default if it’s not mentioned in documentation.

Discontinuing the use of a prescribed medication on the patient’s own initiative (not directed by the patient’s doctor) is coded as an underdosing. Underdosing can never be a principal diagnosis.

When two or more contrasting or comparative diagnoses are documented as “either/or”, they are coded as if the diagnoses were confirmed and the diagnoses are sequenced according to the circumstances of the admission.

Sequence as the principal diagnosis the condition, which after study occasioned the admission to the hospital, even though treatment may not have been carried out due to unforeseen circumstances. For example, if a patient is admitted to the hospital for a hysterectomy due to Uterine cancer, and patient had an Acute MI in the preop area, thereby cancelling the surgery, the Principal diagnosis is Uterine Cancer not Acute MI. Here patient is already admitted to the hospital. On the other hand, if patient comes to the outpatient surgery and develops complications, then the complication is the Principal diagnosis.

Present On Admission:

Present on admission is defined as a condition is present at the time the order for inpatient admission occurs. All the conditions that develop during an outpatient encounter, including emergency department, observation, or outpatient surgery, are considered as present on admission.

POA indicator should be assigned to all the principal and secondary diagnoses. POA indicator can be the following.

Y = present at the time of inpatient admission, there is no required timeframe as to when a provider

N = not present at the time of inpatient admission

U = Unclear documentation to determine if condition is present on admission [Avoid this at all costs]

W = provider is unable to clinically determine whether condition was present on admission or not. [can happen rarely]


The above information is mainly to know how coders interpret what we document. It is helpful to know these rules by ICD-10 as practicing physicians especially hospitalists. Some of the above rules can be confusing as I picked up only those which are not very straight forward for us. So, next time, when you need to document Principal Diagnosis in the chart for the above situations, this information will be helpful.


CD-10-CM Official Guidelines for Coding and Reporting FY 2021.

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3 thoughts on “CDI Documentation Tips for Experienced Hospitalists for 2021”

  1. Good day Sir ,

    I have question on anemia in neoplastic disease coding – As per guidelines if patient is admitted for anemia in neoplastic disease we are sequencing cancer as primary
    My question is if patient has metastatic breast cancer to liver, bone, lungs and admitted for anemia in neoplastic disease management? Which cancer site we are sequencing as primary?? Primary site or any other secondary sites ?(in cases of metastatic cancer -if querying provider for responsible site/cancer for anemia in neoplastic disease the physician query response is — due to metastatic cancer we can’t differentiate

    Kindly suggest me


    • Dr. James S. Kennedy from gave the following answer.

      Great question. No official answer that I am aware of. Since the cancer in both locations contributes to the anemia, one could logically use either the primary or secondary location. On the other hand, the Guidelines also state that the secondary site should be the PDX when treatment is directed ONLY at that site. The word ONLY is key. The treatment is directed to the anemia cause by both sites, thus since the secondary malignancy was not the ONLY site treated, the correct answer is to sequence the primary first if it still exists or is documented to being treated. Wonderful question to send to Coding Clinic, You will have to send a deidentified record with this scenario for them to answer it. Let me know what they say. Good luck!


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