Found an error in the AAPC Healthcare Business Monthly, February 2018 edition. In the Coding/Billing section, article, "Build Up Physical and Occupational Therapy Know How, page 47, the author had an example, Jim who tore his peripheral meniscus. She listed ICD-10-CM codes for the diagnoses in the example, the example how to code a sequela, but Y93.67, Activity was listed. This code is not correct. Per coding rules regarding External Codes, Activity codes are coded "at the time of the injury or other health condition occurred." "Codes from category Y93 are used only once, at the initial encounter for treatment." Also status and place of where the injury occurred are not coded at subsequent encounters or sequela diagnoses. Donna