What is an exception to coding an uncertain diagnosis?

For medical practitioners accurate medical coding is essential as it supports the level of billing, ensures maximum reimbursement and provides meaningful data in patient assessment. Sometimes, physicians may not be able to determine a definitive diagnosis. In such a case, they must document and code for abnormal signs, symptoms, abnormal test results and other conditions that required a patient encounter.

Uncertain diagnoses include conditions that qualify as probable, suspected, questionable, rule out, differential, that are documented in the medical records.

Coding for suspected diagnosis should be done on the basis of symptoms, signs, abnormal test results, or other reason for the visit. For example, while documenting “fever and cough, possible pneumonia”, coding must be done for fever and cough not for pneumonia, as the encounter note does not confirm the diagnosis of pneumonia.
Abnormal test results are acceptable diagnoses when additional tests are negative. For example if an ultrasound shows abnormality, but the follow-up MRI returns negative, then the coding must emphasize the medical necessity for the MRI and the code for abnormal findings must be reported.
Code the confirmed diagnosis based on the results of the diagnostic test along with the code related to signs and symptoms as an additional diagnosis. For example, if a surgical specimen is sent to a pathologist with a diagnosis of “mole” and a diagnosis of “malignant melanoma” is made, then “malignant melanoma” should be the primary diagnosis.
If a complete picture of the patient’s condition is not available from the definitive diagnosis, providers can assign additional symptoms and codes. Unrelated signs and symptoms that may have affected the medical decision making or have an impact on the patient’s care can also be reported.

The above coding guidelines apply to professional services and to services performed in an outpatient setting. For facility diagnosis coding in the inpatient setting, providers can report “suspected” or “rule out” diagnoses as if the condition exists. In case a diagnosis is uncertain at the time of discharge, the condition must be coded as if it existed or was established. The only exception to this rule is HIV. HIV is the only condition that has to be confirmed if it is to be reported in an inpatient setting.

Confirmation does not however, require documentation of HIV tests. The physician’s diagnostic statement which reads the patient is HIV positive or has an HIV-related illness is sufficient.

Accurate coding can also reduce the hassle of audits and minimize denials. The physicians must ensure that the documentation is correct. Outsourcing physician coding to a professional medical coding company is an option available for busy healthcare providers. Professional coders who are experts in medical diagnostic coding, CPT and ICD also use advanced software to ensure that the medical claims are processed correctly. The major advantage of having a good coding team to take care of the medical coding and billing process is that there will be no ambiguity regarding the codes assigned. This makes it easy for the payer to process the claims and pay the due reimbursement without the tedious process of checking and rechecking.

Your June 2012 article “Medical Necessity” (p. 22) is extremely interesting and helpful. However, I would very much like to know the official, authoritative, or regulatory source or guidance of the following:

“Physicians never should report a code that represents a probable, suspected, or ‘rule out’ condition. Although facility billing might consider these unconfirmed circumstances (when necessary), physician billing prohibits this practice.”

The “ICD-9-CM Official Guidelines for Coding and Reporting Sections II.H and III.C” state:1

Uncertain Diagnosis

If the diagnosis documented at the time of discharge is qualified as “probable,” “suspected,” “likely,” “questionable,” “possible,” or “still to be ruled out,” or other similar terms indicating uncertainty, code the condition as if it existed or was established. The bases for these guidelines are the diagnostic workup, arrangements for further workup or observation, and initial therapeutic approach that correspond most closely with the established diagnosis. (Note: This guideline is applicable only to inpatient admissions to short-term, acute-care, long-term care, and psychiatric hospitals.)

In contrast, Section IV.I, regarding outpatient services, states:

Uncertain Diagnosis

Do not code diagnoses documented as “probable,” “suspected,” “questionable,” “rule out,” or “working diagnosis,” or other similar terms indicating uncertainty. Rather, code the condition(s) to the highest degree of certainty for that encounter/visit, such as symptoms, signs, abnormal test results, or other reason for the visit. (Please note that this differs from the coding practices used by short-term, acute-care, long-term care, and psychiatric hospitals.)

I believe that all physicians’ claims for professional services in any setting must use ICD-9-CM for diagnosis coding and must follow these official coding guidelines. The guidelines state:

“Adherence to these guidelines when assigning ICD-9-CM diagnosis and procedure codes is required under the Health Insurance Portability and Accountability Act (HIPAA). The diagnosis codes (Volumes 1-2) have been adopted under HIPAA for all healthcare settings. Volume 3 procedure codes have been adopted for inpatient procedures reported by hospitals.”

There doesn’t appear to be any distinction in these guidelines between physician and facility diagnostic coding, and hospitalists (as well as other admitting physicians) are managing “inpatient admissions,” unless they are working in observation care, which is considered “outpatient” by Medicare. The reference in Sections II.H and III.C to “at the time of discharge” sounds problematic for physician claims for daily inpatient services unless the claim is not submitted until after discharge, at which time it can be determined whether the condition(s) is still qualified as “uncertain.”

Nothing in the guidelines seems to prohibit hospitalists (or other admitting physicians) from assigning “uncertain” diagnoses on claims for inpatient services (in contrast to observation and other outpatient services). If there is any other authoritative regulatory guidance that clarifies or supersedes the official guidelines, I would certainly like to see it.

Thanks so much for helping me with this difficult and confusing billing situation.

Richard D. Pinson, MD, FACP, Chattanooga, Tenn.

Accurate diagnosis coding is crucial for patient care and compliant, optimal reimbursement. In the outpatient setting, you should never assign a diagnosis unless that diagnosis has been confirmed by diagnostic testing, or is otherwise certain. Uncertain diagnoses include those that are:

Probable
Suspected
Questionable
“Rule out”
Differential
Working

If you are unable to determine a definitive diagnosis, you should document and code for the signs, symptoms, abnormal test result(s), or other conditions that prompted the patient encounter. ICD-10-CM coding guidelines confirm, “Each healthcare encounter should be coded to the level of certainty known for that encounter. If a definitive diagnosis has not been established by the end of the encounter, it is appropriate to report codes for sign(s) and/or symptom(s) in lieu of a definitive diagnosis.”
Many signs and symptoms codes are found in ICD-10-CM Chapter 18 (R00.0–R99); however, signs and symptoms codes may appear throughout the ICD-10-CM codebook. Chapter 18 defines signs and symptoms as:

(a) cases for which no more specific diagnosis can be made even after all the facts bearing on the case have been investigated; (b) signs or symptoms existing at the time of initial encounter that proved to be transient and whose causes could not be determined; (c) provisional diagnosis in a patient who failed to return for further investigation or care; (d) cases referred elsewhere for investigation or treatment before the diagnosis was made; (e) cases in which a more precise diagnosis was not available for any other reason;
(f) certain symptoms, for which supplementary information is provided, that represent important problems in medical care in their own right.

For example, you document “Fatigue, suspect iron deficiency anemia,” you should code only for the fatigue because the encounter note does not confirm the diagnosis of iron deficiency anemia. “Abnormal test result” (e.g., Abnormal findings on examination of blood, without diagnosis, R70-R79) is acceptable as a primary diagnosis when ordering follow-up testing based on positive findings. If diagnostic testing confirms a diagnosis, report the definitive diagnosis rather than the signs and symptoms that prompted the test. If the definitive diagnosis fails to present a complete picture of the patient’s condition, you may assign additional signs and symptoms codes. You also may report unrelated signs and symptoms that affect your medical decision-making, or otherwise influence the patient’s care. However, per ICD-10-CM Official Guidelines, “Signs and symptoms that are associated routinely with a disease process should not be assigned as additional codes, unless otherwise instructed by the classification.”

Note that the above coding rules apply to professional services, and to those services performed in an outpatient setting. In the inpatient setting for facility diagnosis coding, you may report suspected or rule out diagnoses as if the condition exists. If a diagnosis is uncertain at the time of discharge, the condition should be coded as if it existed or was established.

HIV Is an Exception

HIV is an exception to the above rule: HIV is the only condition that must be confirmed if it is to be reported in the in-patient setting. Confirmation does not require documentation of positive serology or culture for HIV. The physician’s diagnostic statement that the patient is HIV positive or has an HIV-related illness is sufficient.

Coding Uncertain Diagnoses was last modified: May 9th, 2016 by John Verhovshek