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ICD-10/Z51.0

Z51.0 ICD-10-CM Code: Encounter for antineoplastic radiation therapy

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Inpatient Payment Groups (MS-DRG)

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43.0 (FY2026), Appendix B.

  • MS-DRG 826 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH MAJOR O.R. PROCEDURES WITH MCC (MDC 17)
  • MS-DRG 827 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH MAJOR O.R. PROCEDURES WITH CC (MDC 17)
  • MS-DRG 828 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH MAJOR O.R. PROCEDURES WITHOUT CC/MCC (MDC 17)
  • MS-DRG 829 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH OTHER PROCEDURES WITH CC/MCC (MDC 17)
  • MS-DRG 830 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH OTHER PROCEDURES WITHOUT CC/MCC (MDC 17)
  • MS-DRG 849 — RADIOTHERAPY (MDC 17)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Code Set: Valid FY2026 and FY2027. FY2026 took effect October 1, 2025.

Official Registry Overview & Definition

Encounter for antineoplastic radiation therapy is a billable ICD-10-CM diagnosis code (Z51.0).

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for Z51.0 in the official ICD-10-CM tabular list.

Excludes1 — Not Coded Here

Conditions that can never be reported with this code; the two are mutually exclusive.

  • follow-up examination after treatment (Z08-Z09)

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

  • follow-up examination for medical surveillance after treatment (Z08-Z09)

Code Also

Additional codes that may be required to fully describe the encounter.

  • condition requiring care

Nearest Codes in This Family

Official ICD-10-CM classifications closest to Z51.0 in its code family, with their registry titles.

  • Z51 — Encounter for other aftercare and medical care
  • Z51.1 — Encounter for antineoplastic chemotherapy and immunotherapy
  • Z51.11 — Encounter for antineoplastic chemotherapy
  • Z51.12 — Encounter for antineoplastic immunotherapy
  • Z51.5 — Encounter for palliative care
  • Z51.6 — Encounter for desensitization to allergens
  • Z51.8 — Encounter for other specified aftercare
  • Z51.81 — Encounter for therapeutic drug level monitoring
  • Z51.89 — Encounter for other specified aftercare
  • Z51.A — Encounter for sepsis aftercare

View all codes in the Z51 family

Indexed Clinical Terms (6)

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code.

  • Admission (for), aftercare, radiation therapy (antineoplastic)
  • Admission (for), radiation therapy (antineoplastic)
  • Encounter (with health service) (for), radiation therapy (antineoplastic)
  • Maintenance (encounter for), antineoplastic radiation therapy
  • Radiation, therapy, encounter for
  • Radiotherapy session