Diagnosis Coding and Sequencing FAQ
FAQ 1. How important are
the final diagnoses?
Very important. And notice the emphasis on diagnoses.
The final diagnoses should reflect how difficult the case was, meaning the
complexity of all the medical decision making including laboratory tests,
EKG’s, x-rays, CT’s and treatment that was medically necessary. Since most
claims are transmitted electronically, the quality of your final diagnoses may
determine whether a claim is paid accurately or not.
A common problem is forgetting to list all relevant
diagnoses. Take for example, a patient who passed out, hurt their head and
suffered a laceration. All of the tests listed above may have been medically
indicated. Listing “scalp laceration” as the only diagnosis wouldn’t begin to
accurately reflect all the thought process involved assessing a patient who
also had syncope and a head injury. Frequently multiple diagnoses are required.
FAQ 2. When a patient
has multiple diagnoses, which should be listed first?
If multiple medical problems were addressed and multiple
diagnosis are needed to reflect the complexity of the care delivered, list the
most important or serious condition the patient was treated for first.
For example, a patient may present with leg pain, but
upon evaluation be found to have bilateral pedal edema secondary to new onset
congestive heart failure requiring admission for further evaluation and
treatment. Although the chief complaint may have been leg pain, the diagnosis
of new onset CHF is more serious and would be listed as the first diagnosis.
Whenever a patient requires admission to the hospital, the first diagnosis
should clearly indicate the primary reason for admission.
A chronic condition requiring evaluation, treatment or
factors into your decision-making process when determining management options should
also be listed as a diagnosis. These are often referred to as co-morbidities.
For example: a patient may present with cellulitis, but is found to have
uncontrolled diabetes or hypertension during their visit, It would be
appropriate to list the uncontrolled diabetes and hypertension as diagnoses.
ICD-10-CM Official Guidelines require some conditions and
co-morbidities to be coded together. For
example, a patient with chronic kidney disease (CKD) who is also hypertensive
should always have hypertensive chronic kidney disease coded (I12.-), followed
by the CKD stage (N18.-). A patient with
diabetic foot ulcer would require multiple diagnosis codes describing the type
of diabetes with foot ulcer (E1-.621), along with the laterality, specific foot
location, and stage of the non-pressure foot ulcer (L97.-).
If a patient has multiple fractures, list the most
severe fracture as the primary diagnosis.
If a patient has multiple burns of varying degrees
or thickness, list the most severe burn first. Generally, 3rd degree
burns should be listed before 2nd degree burns, which are listed
before 1st degree/ superficial burns. Additional codes should
be assigned for the percentage of TBSA of the burn and the percentage involving
third degree burns.
FAQ 3. Can symptoms be
used as the diagnosis?
The final diagnosis should always be as specific as
possible. However, if at the end of an encounter, no clear diagnosis can be
established, it is acceptable to code sign(s) and/or symptom(s) instead of a
diagnosis. For example, a patient may present with abdominal pain and after
careful evaluation no definitive cause such as gastritis, cholecystitis,
pancreatitis, or bowel obstruction is identified. “Abdominal pain” would be an
acceptable diagnosis. Note that for accurate ICD-10 code assignment, it
is important to specify the location of the pain such as
epigastric, RUQ, RLQ, etc.
Signs or symptoms that are routinely associated with a
disease process do not need be listed separately. For example, a patient who
presents with chest pain and is found to have an NSTEMI should be coded as an
NSTEMI. There is no need to list the symptom of chest pain as a diagnosis.
FAQ 4. Can I use “R/O”
if I’m not sure of the final diagnosis?
The short answer is no. Medicare’s Evaluation and Management
Guidelines state although your differential diagnoses may include “possible,” “probable,” or “rule out”
to reflect the complexity of your medical decision making, ICD 10 coding rules
state you cannot use R/O, probable, suspected, possible, etc. as diagnosis
codes. Instead, the final
diagnosis should reflect the highest degree of certainty known during the ED
visit. For example, if appropriate
cardiac patients may be diagnosed with STEMI, NSTEMI, unstable angina, or ACS.
If a patient has chest pain of uncertain etiology, it should be classified as
to the type of chest pain (chest wall, precordial, atypical, etc.)
Please note inpatient hospital
coding rules can differ from outpatient coding.
FAQ 5. How do I code SIRS and sepsis given qSOFA and
the new sepsis definitions proposed in the Sepsis 3 article?
Sepsis 3 strives to change how we approach septic
patients clinically, but by itself does NOT change diagnosis coding at this
time. ICD-10 is published by the World Health Organization. In the United
States, the National Center for Health Statistics, which is part of the CDC, is
responsible for adapting it to use in America. Any modifications go through a
thorough evaluation by the WHO & CDC to ensure clinical accuracy and
utility before being adopted. Sepsis 3 made recommendations for code changes,
but until the code changes are reviewed, accepted, and published in ICD-10, providers
and payers should use the existing definitions.
Here is official
advice from Coding Clinic, Third Quarter, 20161.
Question: We have seen the
recently issued consensus definitions for sepsis and septic shock. How and when
will this affect the coding of sepsis and septic shock for ICD-10-CM? Will the
Cooperating Parties be modifying the coding guidelines because of the new clinical
definitions for sepsis?
Answer: The coding
guidelines are based on the ICD-10-CM classification as it exists today.
Continue to code sepsis, severe sepsis and septic shock using the most current
version of the ICD-10-CM classification and the ICD-10-CM Official Guidelines
for Coding and Reporting. Code assignment is based on provider documentation
(regardless of the clinical criteria the provider used to arrive at that
- Copyright 1984-2017, American Hospital Association
("AHA"), Chicago, Illinois.
Please see the list of references in FAQ 10 for more
information on ICD 10 coding.
Here are the four basic choices you currently have when
coding SIRS and Sepsis conditions:
SIRS: Refers to signs and symptoms
associated with a systemic inflammatory response. While Sepsis 3 uses the term
“SIRS” for a patient with ≥ 2 criteria, in ICD-10-CM, SIRS refers to non-infectious conditions such as heatstroke, injury or trauma. Coders will need to specify if
it is associated with organ dysfunction such as kidney failure, liver failure,
or encephalopathy (R65.11) or not (R65.10). The underlying condition (heat
stroke, trauma, etc.) should be listed first, followed by the appropriate code
for SIRS (R65.1x) and then any associated conditions. If a patient has SIRS
related to infection, use the diagnosis of sepsis or severe sepsis as discussed
Refers to patients with a systemic infection, without organ dysfunction (A41).
If identifiable, code the underlying systemic infection.
If at the time of your encounter, the specific organism is not identified, one
may code for Sepsis, unspecified organism
(A41.9). Sepsis due to a procedural complication, Infection following a procedure (T81.4-) or following incomplete spontaneous abortion (O03.37) should be coded
first, followed by the specific infection. Remember, there is no code for a
diagnosis of “urosepsis”. Newborn sepsis
has its own unique code (P36). Note that “bacteremia” (R78.81) (a positive
blood culture without other findings) is not synonymous with sepsis.
SEVERE SEPSIS: Refers to patients with a systemic
infection, with organ dysfunction such as kidney failure, liver failure,
or encephalopathy but without septic shock (R65.20). Severe sepsis requires at
least three codes, and severe sepsis is never the primary code. The first code
is for the underlying infection followed by the subcategory Severe sepsis without septic shock (R65.20).
The provider can still use the code for Sepsis,
unspecified organism (A41.9) as
the first code at the time of presentation if unable to identify the source.
Use additional codes such as Acute kidney
failure (N17.-) or Septic
encephalopathy (G93.41) to specify organ dysfunction.
SEPTIC SHOCK: Refers to patients with a systemic
infection, with organ dysfunction and shock (R65.21). When diagnosing a
patient with septic shock, at least three codes are required just as with
severe sepsis. Septic shock is never a
Urosepsis: There isn’t a unique ICD-10-CM code for this
condition. If the patient is septic without organ dysfunction then list Sepsis, unspecified organism (A41.9) as
the principal diagnosis and Urinary tract
infection, site not specified (N39.0) as contributing. If the patient has
organ dysfunction, e.g. acute kidney failure, list Sepsis, unspecified organism (A41.9) as the principal diagnosis,
Severe sepsis (R65.2-), Acute kidney
failure (N17.-), and Urinary tract
infection, site not specified (N39.0) are listed as contributing diagnoses.
ACEP Quality Improvement & Safety Section Commentary:
Sepsis 3 article: http://jamanetwork.com/journals/jama/fullarticle/2492881
FAQ 6. How do I code for
a patient who is unresponsive since there is no ICD-10 code?
Best practice would be to list the medical condition that
is causing the patient to be unresponsive. Since there is no code for
“Unresponsive”, it would be better to list “Altered mental state”,
“Unconscious”, “Coma”, or “Stupor” if medically appropriate. There are also codes for transient alteration
of awareness (R40.4) and somnolence (R40.0).
The Glasgow Coma Scale (R40.2-) can be coded in
conjunction with traumatic brain injury codes, acute cerebrovascular
disease or sequelae of cerebrovascular disease codes. These codes are primarily
for use by trauma registries, but they may be used in any setting where this
information is collected. The coma
scale may also be used to assess the status of the central nervous system for
other non-trauma conditions. The
coma scale codes should be sequenced after the diagnosis code(s). Three codes, one from each subcategory, are
needed to complete the scale. The 7th character indicates when the scale was
recorded. The 7th character should match for all three codes. There is a GCS code set designated “at
arrival to the Emergency Department.”
also includes a code set for NIH Stroke Scale 0-42 (R29.7- -). The score may be used in conjunction with
acute stroke codes I63 to identify the patient’s neurological status and the
severity of the stroke. These codes
should be sequenced after the acute stroke diagnosis code(s).
FAQ 7. How do I code for
HIV and illnesses associated with HIV?
Patients known to have HIV or AIDS should generally have
this listed as a co-morbid condition as it adds complexity to the medical
decision making. Use additional codes for manifestations of HIV
infection, if present. Z21, Asymptomatic
human immunodeficiency virus [HIV] infection status is to be applied when the
patient without any documentation of symptoms is listed as being “HIV
positive,” “known HIV,” “HIV test positive,” or similar terminology. Patients with any known prior diagnosis of an
HIV-related illness should be coded to B20. Once a patient has developed an
HIV-related illness, the patient should always be assigned code B20 on every
subsequent admission/encounter. Patients previously diagnosed with any HIV
illness (B20) should never be assigned to R75 or Z21, Asymptomatic human
immunodeficiency virus [HIV] infection status.
FAQ 8. For a patient who is admitted, do the Emergency Department
diagnoses and the hospital discharge diagnoses need to match?
Not necessarily. The Emergency
Department diagnosis is based upon the clinical information available and
should always be as specific as possible. The hospital discharge diagnoses may
be the same, different, and may include additional findings. As discussed in
FAQ 4, Emergency physicians may not code “rule out” diagnoses, coding
guidelines for inconclusive diagnoses (probable, suspected, rule out, etc.)
were developed for inpatient reporting and do not apply to outpatients.
FAQ 9. Does the final diagnosis
Yes and no. Coding convention
states that you don’t need a “final” diagnosis but that the diagnosis is to the
level of clinical certainty for the encounter. The diagnosis code(s) help
support medical necessity for the encounter. The level of service a physician
gets paid should be determined by the Nature of the Presenting Complaint
and the Complexity of the Medical Decision Making performed.
However, occasionally payers
violate coding convention and use the final diagnosis to determine payment. Such
a methodology ignores the cognitive work performed by physicians which defines
the Complexity of Medical Decision Making. A patient may present with several
symptoms, require a complex work-up, but be discharged with a
non-life-threatening diagnosis. For example, a patient with a cough,
tachycardia, and chest pain may require extensive testing such as complete
blood count, basic metabolic panel, troponin, EKG, chest x-ray, and CT of the
chest. However, the final diagnosis might be bronchitis which could lead a
payer to wrongly deny the claim or down-code the Evaluation & Management
level of service.
Best practice is to make sure the
final diagnoses reflect all the issues addressed during the ED encounter, how
complex the Medical Decision Making was, and the testing needed. In the example
given above, in addition to diagnosing bronchitis it would likely be helpful to
list tachycardia and chest pain to indicate why such an extensive work-up was
FAQ 10. Where can I learn more about ICD-10-CM?
National Center for Healthcare
Statistics ICD-10-CM website
Official ICD-10 Guidelines: https://www.cdc.gov/nchs/data/icd/10cmguidelines_2017_final.pdf
2017 ICD-10-CM codes (indexes and
For questions about Claims
Processing and Payment or Local Coverage Determinations:
Contact your Medicare
Administrative Contractor (MAC) for guidance. You can find the list of MACs at
this link: https://www.cms.gov/Medicare/Coding/ICD10/ICD-10-Provider-Contact-Table.pdf
Additional resources are located
on the ACEP website:
ICD-10-CM and the Emergency Physician
ICD-10-CM For the Busy Emergency Physician
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