2027 ICD-10-CM Diagnosis Code Z43.9Encounter for attention to unspecified artificial opening
Z43.9 is a billable ICD-10-CM diagnosis code for encounter for attention to unspecified artificial opening. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 951. The code is not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting. Coders also document this condition as ischemia of stoma. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other aftercare encounter.
For Medicare Advantage risk adjustment, Z43.9 maps to CMS-HCC Category 463 (Artificial Openings for Feeding or Elimination) under the V28 model, adding a risk factor of about 0.673 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for Z43.9.
Present on Admission (POA)Billing
Z43.9 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Encounters for other specific health care (Z40-Z53).
Medicare Risk Adjustment (HCC)Billing
Z43.9 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Ischemia of stoma
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to Z43.9: its own notes plus those printed at Z43, block Z40-Z53, and Chapter 21. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- closure of artificial openings
- passage of sounds or bougies through artificial openings
- reforming artificial openings
- removal of catheter from artificial openings
- toilet or cleansing of artificial openings
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
Notes
General instructions on how these codes are used.
- 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:
- (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.
- (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: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name Z43.9, its category, or a range that includes it.
Excludes1 1
These codes carry an Excludes1 note naming Z43.9: they are not reported together with it, unless the two conditions are unrelated.
Excludes2 2
These codes carry an Excludes2 note naming Z43.9: its condition is not part of those codes, and both may be reported when the patient has both.
- Block T80-T88 Complications of surgical and medical care, not elsewhere classifiedclosure of external stoma (Z43.-) names Z43.-, which includes this code
- Z48 Encounter for other postprocedural aftercareencounter for attention to artificial openings (Z43.-) names Z43.-, which includes this code
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Admission (for) See Also: Encounter (for);
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Ostomy
An ostomy is surgery to create an opening (stoma) from an area inside the body to the outside. It treats certain diseases of the digestive or urinary systems. It can be permanent, when an organ must be removed. It can be temporary, when the organ needs time to heal. The organ could be the small intestine, colon, rectum, or bladder.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert Z43.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About Z43.9Overview
What is the ICD-10 code for encounter for attention to unspecified artificial opening?
The ICD-10-CM code for encounter for attention to unspecified artificial opening is Z43.9 (sometimes written as Z439). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is Z43.9 (Encounter for attention to artificial openings) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report encounter for attention to unspecified artificial opening on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does Z43.9 group to?
On inpatient claims, encounter for attention to unspecified artificial opening maps to MS-DRG 951 (other Factors Influencing Health Status), which carries a relative weight of 0.5574. Higher weights mean higher Medicare reimbursement.
Can Z43.9 be a principal diagnosis?
No. The Medicare Code Editor rejects this code as a principal diagnosis because encounter for attention to unspecified artificial opening describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.
Is Z43.9 exempt from POA reporting?
Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for encounter for attention to unspecified artificial opening on inpatient claims. The code appears in the Encounters for other specific health care (Z40-Z53) range of the CMS exempt list.
What HCC is Z43.9?
Z43.9 (encounter for attention to unspecified artificial opening) maps to CMS-HCC Category 463 (Artificial Openings for Feeding or Elimination), commonly written as HCC 463, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 188 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.
Does Z43.9 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, Z43.9 adds a risk adjustment factor of about 0.673 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.526 to 0.947 depending on the payment segment). HCC 463 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 463 category page.
