Lyme Disease ICD-10-CM codes

A69.20 (Lyme disease, unspecified) covers early localized Lyme disease with erythema migrans and any case where the provider does not document a specific organ manifestation. The fifth character identifies disseminated manifestations: A69.21 meningitis due to Lyme disease, A69.22 other neurologic disorders (including facial nerve palsy and radiculopathy), A69.23 Lyme arthritis, and A69.29 other conditions such as Lyme carditis.

The A69.2- codes are combination codes, so the manifestation is not coded separately: do not add G51.0 for Bell palsy or M13.- for arthritis when the provider attributes them to Lyme disease. If the provider documents Lyme carditis with heart block, A69.29 is assigned with an additional code for the conduction disorder (I44.-) because the block itself is not included in the combination code.

A positive serology alone does not support A69.2-; the provider must document Lyme disease. A tick bite without infection is coded as a superficial injury (S-code for the site with the seventh character) plus W57.XXXA for the external cause. After treatment, a history of Lyme disease is Z86.19. Symptoms persisting after completed treatment (post-treatment Lyme disease syndrome) have no specific code; code the documented symptoms and Z86.19.