ICD 10 Coding Alert

You'll need to know the leg involved to choose the best DVT code.

Coding for deep vein thrombosis (DVT) will get a lot more detailed under ICD-10. Here's what you can expect.

Diagnosis: Embolism is the obstruction of a vessel by a clot or foreign substance (such as plaque or fatty deposits). Thrombosis is obstruction by a blood clot. The codes featured here are specific to deep vessels, and that means the codes are appropriate for DVT. The codes are also specific to acute cases, as opposed to chronic.

ICD-9-CM code:

• 453.42, Acute venous embolism and thrombosis of deep vessels of distal lower extremity

ICD-10-CM codes:

• I82.44-, Acute embolism and thrombosis of ... tibial vein
• I82.49-, Acute embolism and thrombosis of other specified deep vein of ... lower extremity
• I82.4Z-, Acute embolism and thrombosis of unspecified deep veins of ... distal lower extremity

Choose the sixth character based on the side involved:

ICD-9 coding rules: Inclusion notes with 453.42 tell you the code is appropriate for diagnoses connected to the calf, lower leg NOS, or the peroneal or tibial veins. Note that peroneal means fibular. Don't confuse it with perineal, which relates to the genital area.

ICD-10 changes: ICD-10 expands your options dramatically, creating codes that differ based on whether the diagnosis involves the right leg, the left leg, both legs, or an unspecified leg. You also must choose among codes that differ based on whether the vein involved is the tibial, another specified vein, or is not specified.

Documentation: Your clinician's documentation will need to be clear about the vessel(s) and limb(s) involved for you to choose the most appropriate ICD-10 code. Remember that "other" means the physician documented the type, but ICD-10 doesn't offer a code specific to the documented type. "Unspecified" means the physician did not document the needed information.

Coder tips: The codes shown here are specific to acute, deep vein, and distal lower extremity diagnoses. You'll see similarly (and sometimes even more) detailed ICD-10 coding options for chronic and proximal lower extremity diagnoses, as well as diagnoses specific to other anatomic features, such as thoracic or upper extremity vessels. If these are diagnoses you see in your practice, take the time to review those new code ranges.

Remember: When ICD-10 goes into effect, you should apply the code set and official guidelines in effect for the date of service reported. Learn more at www.cms.gov/ICD10/ and www.cdc.gov/nchs/icd/icd10cm.htm#10update. The current proposed date for implementation is Oct. 1, 2014.