Pathology/Lab Coding Alert

To clinch proper lab payment for monitoring patients on anticoagulation medication like warfarin (Coumadin), you-ve got to stick to prothrombin time testing's coverage and procedure-coding rules.

Follow these five steps to get the coding right -- every time:

-Physicians often use PT to assess patient response to the drug warfarin,- says Barb Miller, MT (ASCP) SH, clinical lab specialist with Nebraska Medical center in Omaha.

When patients on warfarin therapy come to the lab or -Coumadin clinic- for periodic testing to assess their anticoagulation status, you should report 85610 (Prothrombin time) for the test.

Remember the modifier: If your lab operates with a CLIA certificate of waiver, you-ll need to append modifier QW (CLIA waived test) to 85610.

Labs express PT test results in seconds and/or as an international normalized ratio (INR).

Glitch: Commercial thromboplastin reagents used in laboratory PT tests have different potencies, so the INR reporting method -normalizes- results by reporting the PT ratio that would result if the World Health Organization reference thromboplastin were used to perform the test.

Bottom line: Because you determine INR by a calculation, you don't get additional pay -- reporting INR is part of the service that 85610 describes.

-If the laboratory draws the blood, you might be able to separately report the venipuncture or fingerstick in many cases,- says Peggy Slagle, CPC, billing compliance coordinator at the University of Nebraska Medical Center in Omaha.

You-ll most commonly report your phlebotomist-s

service with one of these codes:

- 36415 -- Collection of venous blood by venipuncture

- 36416 -- Collection of capillary blood specimen

(e.g., finger, heel, ear stick).

Old way: Because labs had to report blood draws to Medicare using G0001 (Routine venipuncture for collection of specimen[s]) until 2005, you might still hear people referring to that code. You should no longer use G0001, however, because Medicare now accepts 36415 for venipuncture service. Medicare will not pay separately for a capillary blood draw (36416 for instance, a finger- or heel- stick).

Catch: Not every payer will reimburse you for blood draws. Some payers consider the service bundled with the lab test.

-Patients may be on anticoagulation therapy for many reasons, but you should not report the underlying condition as the primary code for the PT test,- Slagle says.

Do this: -If the reason for the PT test is to monitor the effectiveness of anticoagulation medication, the primary diagnosis code for the service should be V58.61 (Longterm [current] use of anticoagulants),- Slagle says.

You may report the underlying reason for the warfarin therapy, such as mechanical heart valve (V43.3),pulmonary embolism (415.1x), atrial fibrillation (427.31), or acute myocardial infarction (410.x), as a secondary diagnosis.

Look for other reasons: Warfarin therapy isn't the only reason a physician might order PT. Medicare also considers the test medically necessary for a patient with:

- signs or symptoms of abnormal bleeding or thrombosis

- a personal history associated with bleeding or thrombosis risk related to the extrinsic coagulation pathway, such as lymphoma or HIV

- a history of bleeding or thrombotic abnormality who is going to have an invasive medical intervention.

For a complete list of payable diagnoses, see the Medicare National Coverage Determination (NCD) for PT on the Internet at www.cms.hhs.gov/CoverageGenInfo/downloads/manual200901.pdf#6.

Changes in underlying medical condition or warfarin dosing determine the need for repeat PT tests, so CMS does not establish an across-the-board frequency limitation for this.

On the other hand: CMS states, -In a patient on stable warfarin therapy, it is ordinarily not necessary to repeat testing more than every two to three weeks.-