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ICD-10-CM Z79.624: Long term (current) use of inhibitors of nucleotide synthesis

Z79.624 is the billable ICD-10-CM code for long term (current) use of inhibitors of nucleotide synthesis, in category Z79 (Long term (current) drug therapy) of the Persons with potential health hazards related to family and personal history and certain conditions influencing health status section. As a principal diagnosis it groups to MS-DRG 949 Aftercare with CC/MCC, MS-DRG 950 Aftercare without CC/MCC (MDC 23 MDC 23: Factors Influencing Health Status and Other Contacts with Health Services). 1 LCD billing and coding article lists it as covered.

Compiled from CMS files by the QuickIntell RCM Editorial Team · Data effective · Method: reference methodology · Report a data correction

Data currency: ICD-10-CM code descriptions: FY2027 (effective October 1, 2026); IPPS Table 5 (MS-DRG weights): v44 FY2027 (final rule + CN3) (effective October 1, 2026); ICD-10-CM to HCC mapping: PY2027 initial ICD-10-CM mappings (dates of service 2026) (payment year 2027); Medicare Coverage Database billing and coding articles: MCD release October 8, 2026 (effective October 4, 2026). Next CMS release: FY2028 code files, effective October 1, 2027 for the ICD-10-CM code descriptions; FY2028 final rule (August 2027), effective October 1, 2027; an April 1 interim grouper update when CMS issues one for the IPPS Table 5 (MS-DRG weights); PY2028 advance notice (February 2027) and the PY2027 midyear final mapping (spring 2027) for the ICD-10-CM to HCC mapping; weekly, every Thursday for the Medicare Coverage Database billing and coding articles.

Code
Z79.624
billable FY2027 ICD-10-CM code
Category
Z79 Long term (current) drug therapy
Chapter
21: Factors influencing health status and contact with health services (Z00-Z99)
CC/MCC (MS-DRG v44)
Neither
CMS-HCC V28
Not mapped
POA reporting
Exempt

Tabular list notes for Z79.624

The tabular list has no notes on Z79.624 itself; the notes below apply from its parent headings.

Inherited from Z79 (Long term (current) drug therapy)

Includes
  • long term (current) drug use for prophylactic purposes
Excludes2 (not part of this condition, may be coded together)
  • drug abuse and dependence (F11-F19)
  • drug use complicating pregnancy, childbirth, and the puerperium (O99.32-)
Code also
  • any therapeutic drug level monitoring (Z51.81)

Inherited from Z79.6 (Long term (current) use of immunomodulators and immunosuppressants)

Excludes2 (not part of this condition, may be coded together)
  • long term (current) use of steroids (Z79.5-)
  • long term (current) use of agents affecting estrogen receptors and estrogen levels (Z79.81-)

MS-DRG grouping when Z79.624 is the principal diagnosis

MS-DRG v44 groups for Z79.624 as principal diagnosis
MDCMS-DRGs
23 MDC 23: Factors Influencing Health Status and Other Contacts with Health Services949950

The final group also depends on procedures, secondary diagnoses and discharge status; the MS-DRG lookup for Z79.624 shows the full grouping logic.

CC/MCC status and inpatient edits

Z79.624 is neither a CC nor an MCC under MS-DRG v44, so as a secondary diagnosis it does not raise the MS-DRG severity level. Check Z79.624 against a principal diagnosis.

  • Present on admission: exempt from POA indicator reporting (FY2027 exempt list).
  • Medicare Code Editor: unacceptable principal diagnosis.

CMS-HCC V28 risk adjustment

Z79.624 does not map to a payment HCC in the PY2027 CMS-HCC V28 model, so on its own it does not change a Medicare Advantage risk score.

LCD billing and coding articles that list Z79.624

1 current Medicare billing and coding article lists Z79.624 among the diagnoses that support medical necessity for the services they cover.

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Frequently asked questions

What does ICD-10-CM Z79.624 mean?

Z79.624 means long term (current) use of inhibitors of nucleotide synthesis. It is one of 25 billable codes under Z79, long term (current) drug therapy.

Which MS-DRG does Z79.624 group to?

As the principal diagnosis, Z79.624 groups to MS-DRG 949 Aftercare with CC/MCC, MS-DRG 950 Aftercare without CC/MCC (MDC 23 MDC 23: Factors Influencing Health Status and Other Contacts with Health Services) under MS-DRG v44, before procedures and secondary diagnoses are applied.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.

Disclaimer

The descriptor and notes are reproduced from the FY2027 ICD-10-CM files; MS-DRG, CC/MCC and HCC facts come from the CMS FY2027 and PY2027 tables. Code from the medical record and the ICD-10-CM Official Guidelines. Not legal, clinical or billing advice.

Found a figure that does not match the CMS file? Report a data correction with the CMS file and the value you expected; the request reaches the editorial team through the contact form.