New for FY2027 ICD-10-CM · October 1, 2026
Z86.17: Personal history of Clostridioides difficile infection
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Personal history of Clostridioides difficile infection. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Billable code. Verified against the official FY2027 order file.
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Instructional note
Z codes represent reasons for encounters. A corresponding procedure code must accompany a Z code if a procedure is performed. Categories Z00-Z99 are provided for occasions when circumstances other than a disease, injury or external cause classifiable to categories A00-Y89 are recorded as 'diagnoses' or 'problems'. This can arise in two main ways:
Source: Z00-Z99 (chapter, inherited).
Instructional note
(a) When a person who may or may not be sick encounters the health services for some specific purpose, such as to receive limited care or service for a current condition, to donate an organ or tissue, to receive prophylactic vaccination (immunization), or to discuss a problem which is in itself not a disease or injury.
Source: Z00-Z99 (chapter, inherited).
Instructional note
(b) When some circumstance or problem is present which influences the person's health status but is not in itself a current illness or injury.
Source: Z00-Z99 (chapter, inherited).
Code also
any follow-up examination (Z08-Z09)
Source: Z77-Z99 (section, inherited).
Code first
any follow-up examination after treatment (Z09)
Source: Z86 (category, inherited).
Instructional note
Conditions classifiable to A00-B89, B99
Source: Z86.1 (self, inherited).
Excludes1
personal history of infectious diseases specific to a body system
Source: Z86.1 (self, inherited).
Excludes1
sequelae of infectious and parasitic diseases (B90-B94)
Source: Z86.1 (self, inherited).
Instructional note
Personal history of Clostridium difficile colitis (fulminant) (nonfulminant)
Source: Z86.17 (self, direct).
Instructional note
Personal history of foodborne intoxication by Clostridium difficile
Source: Z86.17 (self, direct).
Instructional note
Personal history of Pseudomembraneous colitis
Source: Z86.17 (self, direct).
Excludes1
enterocolitis due to Clostridium difficile, recurrent (A04.71)
Source: Z86.17 (self, direct).
Compare the FY2027 additions, removals and billable-status changes
What does Z86.17 mean in FY2027?
The official ICD-10-CM descriptor is Personal history of Clostridioides difficile infection. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
When did Z86.17 become an ICD-10-CM code?
Z86.17 is new for FY2027 ICD-10-CM, effective October 1, 2026. It is absent from the FY2026 April order file. Use the code set that applies to the encounter or inpatient discharge date, and check the official Tabular instructions.
Is Z86.17 billable in FY2027?
The FY2027 order file marks Z86.17 as billable. Check the complete Tabular instructions and documentation before assigning it.
Does Z86.17 map to an HCC?
Z86.17 is not in the current CMS mapping file (it is new for FY2027), and CMS has not yet published payment year 2028 mappings. No HCC category or RAF coefficient is shown.
Source: CMS FY2027 ICD-10-CM order file. Payment model: CMS CY 2027 Rate Announcement. Read the FY2027 Official Guidelines.