Z79.623 — Long term (current) use of mammalian target of rapamycin (mTOR) inhibitor
Is Z79.623 billable?
Yes — Z79.623 is billable for FY2027. Z79.623 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. Z79.623 may be submitted for encounters from October 1, 2026 through September 30, 2027.
Z79.623 at a glance
| Code | Z79.623 |
|---|---|
| Description | Long term (current) use of mammalian target of rapamycin (mTOR) inhibitor |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
What Medicare edits apply to Z79.623?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name Z79.623 directly.
CMS will reject this code as the principal diagnosis on an inpatient claim. It describes something other than the condition chiefly responsible for the admission.
Which MS-DRGs does Z79.623 group to?
Z79.623 sits in MDC 23 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 949Aftercare with CC/MCCmedical
- 950Aftercare without CC/MCCmedical
How is Z79.623 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to Z79.623. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Long-term › mammalian target of rapamycininhibitor (current) (prophylactic) drug therapy (use of)
- Long-term › sirolimus (current) (prophylactic) drug therapy (use of)
Inclusion terms
Alternative wording in documentation that is classified to Z79.623.
- Long term (current) use of sirolimus
Excludes2 — not included here — inherited from Z79
The conditions below are not part of Z79.623, but a patient may have both at the same time. When documentation supports it, Z79.623 and the excluded code may both be reported.
Excludes2 — not included here — inherited from Z79.6
The conditions below are not part of Z79.623, but a patient may have both at the same time. When documentation supports it, Z79.623 and the excluded code may both be reported.
Code also — inherited from Z77-Z99
Two codes may be needed to describe the condition fully. Whether Z79.623 is sequenced first depends on the reason for the encounter.
- any follow-up examination (Z08-Z09)
Code also — inherited from Z79
Two codes may be needed to describe the condition fully. Whether Z79.623 is sequenced first depends on the reason for the encounter.
- any therapeutic drug level monitoring (Z51.81)
How long has Z79.623 existed?
Z79.623 first appears in FY2023.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.