The codes for factors influencing health and contact with health services represent reasons for encounters. In ICD-10-CM, these codes are located in Chapter 21 and have the initial alpha character of “Z,” so codes in this chapter eventually may be referred to as “Z-codes” (just as the same supplementary codes in ICD-9-CM were referred to as “V-codes”). While code descriptions in Chapter 21, such as aftercare, may appear to denote descriptions of services or procedures, they are not procedure codes. These codes represent the reason for the encounter, service or visit, and the procedure must be reported with the appropriate procedure code.

Aftercare codes are found in categories Z42-Z49 and Z51. Aftercare is one of the 16 types of Z-codes covered in the 2012 ICD-10-CM Official Guidelines and Reporting. Aftercare visit codes cover situations occurring when the initial treatment of a disease has been performed and the patient requires continued care during the healing or recovery phase, or care for the long-term consequences of the disease.

Reporting Encounters for Aftercare

Reporting rules for aftercare are as follows:

  • The aftercare Z-code should not be used if treatment is directed at a current, acute disease. The diagnosis code is to be used in these cases. Exceptions to this rule include:
    • Codes for encounters for antineoplastic radiation, chemotherapy and immunotherapy (Z51.0, Z51.1-) are assigned if the sole reason for the encounter is antineoplastic therapy – even if the patient still has the neoplastic disease.
    • Aftercare for injuries is not reported with Z-codes. Assign the Z-code with the appropriate seventh character for subsequent care.
  • The aftercare codes are generally the first listed diagnosis.
  • Aftercare codes should be used in conjunction with other aftercare codes, diagnosis codes and/or other categories of Z-codes to provide better detail on the specifics of the aftercare encounter/visit, unless otherwise directed by the classification.
  • Certain aftercare Z-codes require a secondary diagnosis code to describe the resolving condition or sequela. For other aftercare codes, the condition is included in the code description and a secondary diagnosis is not required.

Examples of Aftercare Coding

Two examples of aftercare coding in ICD-10-CM are provided. The first is an example of aftercare reported with a Z-code from Chapter 21. The second shows how aftercare for an injury is reported.

Aftercare Following Explantation of Joint Prosthesis

Aftercare following explantation of a joint prosthesis is reported with a code from category Z47, denoting orthopedic aftercare. Aftercare following explantation of a joint prosthesis (Z47.3-) may be reported for a staged procedure or an encounter for evaluation of planned insertion of a new joint prosthesis following prior explantation of a joint prosthesis. In ICD-10-CM, aftercare for explantation of a joint prosthesis is specific to site.

Example 1

The patient is a 64-year-old Caucasian male, now eight weeks post-explantation of a left knee prosthesis, who is here today to have his left knee checked and to determine if a new prosthesis can be implanted. This retired chemical engineer had a total knee arthroplasty four months ago and developed a staphylococcus coagulase negative wound infection postoperatively. After local surgical debridement and IV antibiotics failed to clear the infection, the prosthesis was removed and a vancomycin-loaded polymethylmethacrylate cement spacer was inserted into the suprapatellar pouch, with extension to the gutters. The patient has had PT support two to three times a week and serum CRP has been monitored weekly. CRP is WNL for the second week in a row. The left knee has no redness or swelling, and surgical incisions are clean and dry. The infection appears to have cleared up. The patient is anxious to have a new implant because he has a trip planned in three months. Arrangements will be made by the surgery scheduler after he has been cleared by his PMD. He is given orders for preoperative lab work, EKG and chest X-ray.

Reason for encounter: Z47.33 Aftercare following explantation of knee joint prosthesis

Aftercare for Healing Traumatic Fracture of Lower Leg

Aftercare for injuries is reported with a V-code in ICD-9-CM. However, aftercare of injuries in ICD-10-CM is captured with the seventh character “D,” specifically denoting routine care following most injuries. For fractures, additional seventh characters for subsequent encounters apply, depending on whether the fracture is open or closed and whether the healing is routine or delayed, with nonunion or malunion.

Example 2

Consider a 37-year-old Caucasian male reporting to the orthopedic clinic for a cast change and possible application of functional brace. The patient sustained a closed, nondisplaced transverse fracture of the right tibial shaft in a snowmobile accident four weeks ago. The fracture initially was treated in the ER with application of a long posterior splint, and the leg subsequently was casted in plaster four days later from mid-thigh to the metatarsal heads (with knee extended and ankle in 90-degree flexion). Radiographs in plaster two weeks ago showed good approximation of the fracture and some callus formation, and repeat films today show the same, with callus size increasing. The cast is removed and the patient is fitted with a functional brace. He will continue to use crutches until evaluated by physical therapy. The first available PT appointment is in one week. RTC for X-ray and recheck of brace in two weeks, or sooner if problems arise.

Reason for encounter: Aftercare for traumatic fracture is reported with code S82.224D, Nondisplaced transverse fracture of shaft of right tibia, subsequent encounter for closed fracture with routine healing.

In the example above, an additional external cause code indicating a snowmobile accident also should be reported.


When the reason for an encounter is aftercare following a procedure or injury, the 2012 ICD-10-CM Official Guidelines and Reporting should be consulted to ensure that the correct code is assigned. Codes for reporting most types of aftercare are found in Chapter 21. However, aftercare related to injuries is reported with codes from Chapter 19, using seventh-character extensions to identify the service as aftercare.

About the Author

Lauri Gray, RHIT, CPC, has worked in the health information management field for 30 years. She began her career as a health records supervisor in a multi-specialty clinic. Following that she worked in the managed care industry as a contracting and coding specialist for a major HMO. Most recently she has worked as a clinical technical editor of coding and reimbursement print and electronic products. She has also taught medical coding at the College of Eastern Utah. Areas of expertise include: ICD-10-CM, ICD-10-PCS, ICD-9-CM diagnosis and procedure coding, physician coding and reimbursement, claims adjudication processes, third-party reimbursement, RBRVS and fee schedule development. She is a member of the American Academy of Professional Coders (AAPC) and the American Health Information Management Association (AHIMA).

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