Let ICD-9-CM guidelines lead you to the correct diagnosis code

Need a break from anatomy and physiology, but still want to prepare for ICD-10-CM? Read the ICD-9-CM and the ICD-10-CM guidelines front to back. You might be surprised at how much you learn and how similar the guidelines are.

It may make the upcoming transition less scary, says Jill M. Young, CPC, CEDC, CIMC, president of Young Medical Consulting in East Lansing, MI.

You can find the current ICD-9-CM and ICD-10-CM guidelines online. The changes to the guidelines appear in red, which makes it easier to spot the differences. But coders who haven’t read the guidelines in their entirety “are missing some phenomenal information,” Young says.

Not surprisingly, the guidelines emphasis the need for consistent, complete documentation in the medical record. Coders shouldn’t pick a code because they think that’s what the physician meant, Young says.

Coders need to review the guidelines annually, just like they do the ICD-9-CM codes, says Shannon E. McCall, RHIA, CCS, CCS-P, CPC, CEMC, CPC-I, CCDS, director of HIM and coding at HCPro, Inc., in Danvers, MA. And that includes the chapter-specific guidelines as well.

The basic ICD-9-CM conventions apply to all settings, so inpatient, outpatient, and professional service coders all need to know them. But coding guidelines can change depending on the setting. The Official Guidelines for Coding and Reporting have dedicated sections for guidance that is specific to individual settings. Sections II and III are inpatient coding concepts, while Section IV is limited to outpatient coding.

That can be a little confusing for coders who handle both inpatient and outpatient claims or for those who code for both facility and professional services, McCall says. A coder at a small facility may report the facility portion of an inpatient admission, for example.

That same coder may then end up coding the evaluation and management professional services for one of the physicians who treated that patient in the hospital. The coder will still use the CPT® codes for the physician’s services.

Consider the following situation. A physician documents “probably blood loss anemia” as the reason for the inpatient admission. Coders in the professional services setting can’t assign a code for the probable diagnosis. Therefore they would have to code based on the highest level of certainty, which could be as small as a symptom, McCall says. “Even though you are coding for an inpatient in the hospital, you are coding for the professional services at that point.”

Sequencing codes
Many of the chapter-specific guidelines focus on the correct sequencing of codes and choosing a principal diagnosis. Those concepts are more important to inpatient coding and in fact, principal diagnosis is only used for inpatient admissions.

For example, in the guidelines for reporting HIV, ICD-9-CM states:

If a patient is admitted for an HIV-related condition, the principal diagnosis should be 042, followed by additional diagnosis codes for all reported HIV-related conditions.

Inpatient coders need to review the record to determine why the patient was admitted and sequence the codes based on that information. Outpatient and physician services coders don’t need to worry about that.

When it comes to sequencing, hospital inpatient and hospital outpatient coders have a different perspective on the importance of the order that the codes go in,” McCall says.

ICD-9-CM codes help support the medical necessity of services provided in outpatient and professional office settings. In those settings, coders need to link together the pertinent diagnosis with the procedure the physician performed. “So whether that code is listed as the first, second, third, or fourth code isn’t really going to be as germane because you are going to link the procedure and the diagnosis,” McCall says.

Consider a hospital outpatient with an HIV-related respiratory condition who is seen for a bronchoscopy. Technically, when it comes to reimbursement for the service, it may not matter if ICD-9-CM code 042 is in diagnosis box one and the respiratory condition is in box two or vice versa, McCall says. As long as the respiratory condition or the HIV code supports the medical necessity of the bronchoscopy, it may not matter which order coders report them in.

However, if a patient is admitted as an inpatient with an HIV-related respiratory condition and the patient’s HIV is symptomatic, coders must report ICD-9-CM code 042 as the principal diagnosis based on the sequencing guidelines. The coder should assign the admission to an MS-DRG in Major Diagnostic Category (MDC) 25 for HIV versus the one for respiratory disorder, McCall says.

Etiology and manifestation guidelines
Some conditions have both an underlying cause and affect multiple body systems. For these conditions, coders must follow the ICD?9?CM coding convention that requires the underlying condition be sequenced first followed by the manifestation. Coders will find a “use additional code” note at the etiology code, and a “code first” note at the manifestation code.

Most, though not all, manifestation codes say “in diseases classified elsewhere,” Young explains. Never code that first because these codes are part of the manifestation convention. The codes that don’t include this language generally say “use additional code” instead. The sequencing rules still apply.

In addition to the notes in the tabular section, these conditions also have a specific index entry structure. The index lists both conditions together with the etiology code first followed by the manifestation codes in brackets. Always sequence the code in brackets second.

“Make sure you look in the alphabetic and numeric section to make sure you have the right number and mix of codes,” Young says.

Signs, symptoms, and uncertain diagnoses
When the physician is unable to make a definitive diagnosis, coders report the signs and symptoms. Coders can find many, but not all, of the symptom codes in Chapter 16 of ICD?9?CM, Symptoms, Signs, and Ill-defined conditions (codes 780.0–799.9).

Coders generally should not report codes for signs and symptoms once the physician provides or confirms a definitive diagnosis. If the physician puts both the diagnosis and the symptoms in the record, coders should query the physician. “Ask, ‘Did you mean for me to code both?’ Sometimes the answer is yes,” Young says.

Coders should not assign additional codes for signs and symptoms that are associated routinely with a disease process, unless otherwise instructed by the classification, according to the official ICD-9-CM guidelines. Coders should report additional signs and symptoms that may not be associated routinely with a disease process when present.

Signs and symptoms also help establish the medical necessity for laboratory tests, especially if the test is negative.

Correct reporting of an uncertain diagnosis is very different for inpatient and outpatient coding, McCall says. The ICD-9-CM guidelines in section II, Selection of Principal Diagnosis, state:

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, long-term care and psychiatric hospitals.

In the outpatient setting, coders cannot code anything that isn’t a confirmed diagnosis, McCall says. In section IV, Diagnostic Coding and Reporting Guidelines for Outpatient Services, the ICD-9-CM guidelines state:

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: This differs from the coding practices used by short-term, acute care, long-term care, and psychiatric hospitals.

Chronic, acute, or both
Some conditions, such as bronchitis, can be acute or chronic. In some cases, a patient can have both an acute and chronic form of the condition. For example, a smoker with chronic bronchitis flies home on a plane full of sick people. As a result, the smoker ends up with acute bronchitis.

Provided the physician has adequately documented the acute and chronic bronchitis, coders should report both because they are two different conditions, Young says. Report the acute condition first.

E-mail your questions to Senior Managing Editor Michelle A. Leppert, CPC-A, at mleppert@hcpro.com.

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