Pathology/Lab Coding Alert

The new ICD9 Codes that will go into effect Oct. 1, 2000, include the expansion of several codes to require an additional digit. That should serve as a reminder to coders that officials from the Health Care Financing Administration (HCFA) and many third-party payers expect specific diagnosis coding. Ignoring those expectations may lead to claims denials and audits.

Coders can make the error of non-specific diagnosis coding in two ways. One is the assignment of a truncated code, which means reporting fourth and fifth digit codes only to the third or fourth digit, respectively. As the Official ICD-9-CM Guidelines for Coding and Reporting explains, A code is invalid if it has not been coded to the full number of digits required for that code.

The second way coders err is in the overuse of unspecified (NOS) codes. The guidelineswhich are approved by HCFA, the American Hospital Association, the American Health Information Management Association, and the National Center for Health Statisticsalso warn against this, stating codes labeled unspecified are used only when neither the diagnostic statement nor a thorough review of the medical record provides adequate information to permit assignment of a more specific code.

Medicare and many third-party payers consider truncated coding invalid and question the overuse of unspecified codes. Clearly there are times when some of these codes must be used for lack of more definitive information, states Stacey Hall, RHIT, CPC, CCS-P, director of corporate coding for Medical Management Professionals Inc. in Chattanooga, Tenn., a national billing and management firm for hospital-based physician practices. But they should not be reported when a more specific diagnosis is evident from the medical record.

By observing a few simple guidelines, however, coders can ensure that they are meeting HCFA and other payers requirements to report diagnoses to the highest degree of specificity.

1. More digits equals more detail. ICD-9 contains codes with three, four or five digits. Most three-digit codes serve as headings for broad categories, which need to be further divided. Categories are subdivided by adding a decimal pointas well as a fourth and/or fifth digitafter the third digit. The fourth and fifth digits provide more detail about the nature of the disease or condition. Those codes with fourth digits are called subcategory codes, while those with fifth digits are sub-classifications. The rule is, if a fourth or fifth digit is available, you must use it.

For example, Coding for gallstones (574) requires a good understanding of these principles, says Hall. The
stones (calculus) can occur in the gallbladder or the bile duct, and they can occur with or without inflammation (cholecystitis) or obstruction.

The fourth digit indicates the location of the calculus, as well as the absence or presence and character of inflammation. For example, 574.2 indicates stones in the gallbladder with no mention of inflammation, while 574.3 indicates stones in the bile duct with acute inflammation, Hall explains.

You cannot report those codes as four digits, she
continues. You are required to code these to the fifth
digit, which means adding 0 if there is no mention of
obstruction in the medical record, or a 1 if obstruction
is reported.

Hall also points out that inflammation of the gallbladder, without any mention of calculus, is reported using codes 575.0 (acute cholecysitis) or 575.1x (other cholecystitis ). Its important to note that the same condition, in the presence or absence of another condition, receives a different code, so you have to read all the options in the tabular list very carefully she advises.

Also, uterine leiomyoma (218) cannot be coded using
three digits only, but must be characterized further
according to location: 218.0 (submucosa), 218.1
(intramural), 218.2 (subserous).

It is especially important to report the most definitive diagnoses in these cases, rather than unspecified (218.9), reports Edward J. Wilkinson, MD, vice chairman of the department of pathology and laboratory medicine at the University of Florida in Gainesville, and president of the American Society for Colposcopy and Cervical Pathology. The location can have a significant impact on the clinical behavior of the condition, he continues. Submucous leiomyoma of the uterus is more prone to abnormal bleeding.

Under the new ICD-9 guidelines, the old code 600 (hyperplasia of prostate) becomes invalid, as coders will be required to report the condition to the fourth digit. The expanded codes are 600.0 (hypertrophy [benign] of prostate), 600.1 (nodular prostate), 600.2 (benign localized hyperplasia of prostate), 600.3 (cyst of prostate), and 600.9 (unspecified hyperplasia of prostate).

This will affect diagnostic coding for the results of prostate biopsies and TURPs (transurethral resection of prostate, 88305), reports Rose Mary Hinrichsen, owner of Medicorp Medical Management Services, a multi-specialty billing and management company in Laguna Niguel, Calif.

Well have to retrain ourselves to use these new codes, and ensure that our pathologists are aware of the need for more specific diagnostic information to avoid overuse of 600.9.

2. Use three-digit codes only when most specific. Use a three-digit diagnostic code only when no fourth or fifth digit is available. Of the hundreds of diagnostic entries, only about 100 three-digit codes are valid without any further specificity. Of these, the following examples are used in pathology coding.

Some of the complications of pregnancy codes only
require three digits, such as 630 for hydatidiform mole, 631 for blighted ovum, and 632 for missed abortion (early fetal death and retention), reports Wilkinson.

Certain neoplasms require a three-digit code that isnt further subdivided, including malignant placenta (181), malignant prostate (185), thyroid-malignant (193), thyroid-benign (226), benign breast (217) and benign ovary (220). Even so, you must read these codes carefully in the tabular list, as they list many exclusions and coding directions for additional codes.

According to Hall, other three-digit codes that
pathologists may encounter include 605 (adherent or
tight foreskin), 470 (deviated nasal septum), and 700 (corns and callosities).

3. Select diagnostic coding resources carefully. Hall reminds coders that they need an up-to-date ICD-9 coding manual. The codes are amended annually, and coders must have the most current information in order to code correctly.

She also suggests that coders use a manual that provides coding direction. This might include a color key that identifies codes that cannot be reported as three digit codes, and codes that should be used with caution because they are unspecified. The most useful code books are flagged in both the alphabetic index (volume 2) and the tabular list (volume 1) to indicate the need for fourth or fifth digit coding.

4. Use coding resources accurately. Remember that entries in the alphabetic index often do not contain fifth digits. Thats why you should never code directly from the index, Hall advises. Instead, you should use the index to direct you to the coding options in the tabular list and select the code from there.

Hall also cautions coders to search the tabular list thoroughly. Depending on the category, the sub-classification may be listed several pages after the start of the listing. In addition, be sure to heed any direction that would point you to an entirely different family of codes, such as the word excludes.

For example, if a specimen is received that demonstrates malignant neoplasm of the body of the uterus, but the origin is unclear due to overlapping sites, the correct code would be 182.8 (malignant neoplasms; other specified sites of body of uterus). The direction under the code explicitly states, excludes malignant neoplasm of uterus not otherwise specified (179). Code 179 is a non-specific code reserved for cases when there is no indication of the source of the specimen (whether it be cervix, body of uterus or uterine adnexa).

5. Avoid catchall codes. Because they are ill defined, Medicare and other payers carefully scrutinize unspecified codes. These codes should be used only when youve checked all other options, Hall warns. For example, code 626.9 (disorders of menstruation, unspecified) is a catchall. I see it used often, reports Wilkinson. It may be used because the clinical problem is as yet unknown, but often a more definitive diagnosis could be assigned once the condition is better defined.

According to Hall, pneumonia often is lumped under
the catchall code, 486 (pneumonia, organism
unspecified). Although this is a legitimate diagnosis
if no other information is available, it would be rare
for laboratory coding. Typically, lab tests would be
instrumental in identifying the causative organism,
and the pneumonia would be reported using more
specific codes (480-484).

If you find yourself ready to assign a catchall code, go back to the medical record and look for information that is more definitive. For surgical pathology specimens, hopefully the surgeon has given the pathologist enough information regarding the patient history and source of the specimen to assign a definitive diagnosis, says Hinrichsen. Similarly, it is important that laboratories receive accurate diagnostic information from physicians, even if in the form of signs and symptoms, to establish medical necessity for lab tests. Although coders may sometimes need to request clarification from the attending physician, Hall recommends you should code only what is documented in the chart.

6. Understand the difference between unspecified and other specified. Coders need to understand the difference between unspecified (NOS) and other specified (NEC) as it is used in ICD-9-CM, states Hall. When coding benign neoplasms of the skin (216), for example, the fourth digit is assigned based on the location of the lesion.

A lesion removed from an area that is listed in ICD-9, such as the lip, scalp, upper limb, etc., should be coded accordingly. A benign neoplasm removed from the neck, therefore, would be coded 216.4, not 216. If the medical record states the location of the lesion, but it is not a site listed in ICD-9, the coder should report 216.8 (other specified sites of skin), says Hall. But if the medical record gives no indication of the source of the lesion, it would be coded 216.9 (skin, site unspecified).

7. Pathologists should use signs and symptoms (780-799) infrequently. Because the pathologist typically determines a diagnosis based on the tissue examination or test results, coding for signs and symptoms is not common in pathology, says Hinrichsen. As stated in the Guidelines, outpatient coding requires reporting the diagnosis to the highest degree of certainty for that encounter.

Coding to the highest degree of certainty means coding for compliance and reimbursement. To accomplish these goals, coders should avoid truncated codes and unspecified diagnoses whenever possible, while assigning codes consistent with the information available in the medical record.