Pathology/Lab Coding Alert

Question: When a patient has a tick bite and the clinician orders a test for suspected Lyme disease, what diagnosis and procedure codes are appropriate?  

Maine Subscriber

Answer: The procedure code depends on what test your lab performs. Based on Centers for Disease Control and Detection (CDC) recommendation, most insurers cover a two-tier testing algorithm that involves an initial test for antibodies, such as  86618 (Antibody; Borrelia burgdorferi (Lyme disease)), followed by a confirmatory test if the initial test is positive:  86617 (Antibody; Borrelia burgdorferi (Lyme disease) confirmatory test (eg, Western Blot or immunoblot)).

Other tests for B. burgdorferi antibody include the following two proprietary laboratory analyses (PLA) codes:

•  0041U (Borrelia burgdorferi, antibody detection of 5 recombinant protein groups, by immunoblot, IgM)
•  0042U (Borrelia burgdorferi, antibody detection of 12 recombinant protein groups, by immunoblot, IgG).

Some carriers won’t cover testing for a patient with a known tick bite and evidence of the characteristic rash (erythema migrans, A69.2, Erythema chronicum migrans due to Borrelia burgdorferi), which may be considered definitive for Lyme disease diagnosis.

Payers don’t generally cover antigen testing for B. burgdorferi, such as the following:

•  87475 (Infectious agent detection by nucleic acid (DNA or RNA); Borrelia burgdorferi, direct probe technique)
•  87476 (Infectious agent detection by nucleic acid (DNA or RNA);
•  Borrelia burgdorferi, amplified probe technique).

Regarding the diagnosis codes, the clinician should provide a list of the signs and symptoms that indicate the need for the testing, such as fever and fatigue and an indication of the tick bite, if known, such as (W57.XXXA Bitten or stung by nonvenomous insect and other nonvenomous arthropods, initial encounter). Note that this is an external cause code so you shouldn’t list it first on the claim. Some payers expect the first code for tick bite to be an insect bite code indicating the bite location, such as S80.861A (Insect bite (nonvenomous), right lower leg, initial encounter), despite the fact that ticks are arthropods, not insects.