C79.9: Secondary malignant neoplasm of unspecified site

C79.9, secondary malignant neoplasm of unspecified site, is listed as a covered diagnosis in 7 Medicare billing and coding articles that apply to 64 HCPCS Level II codes, including C8925 (Transesophageal echocardiography (tee) with contrast, or…), C8926 (Transesophageal echocardiography (tee) with contrast, or…), C8927 (Transesophageal echocardiography (tee) with contrast, or…). The articles come from 3 Medicare contractors. A listed diagnosis supports medical necessity only; coverage still depends on the LCD's criteria and on documentation in the medical record.

HCPCS Level II codes with C79.9 as a covered diagnosis

CodeDescriptionMedicare coverageDMEPOS fee 2026 (state range)Articles listing it
C8925Transesophageal echocardiography (tee) with contrast, or without contrast followed by with contrast, real time with image documentation (2d) (with or without m-mode recording); including probe placement, image acquisition, interpretation and reportSpecial coverage instructions apply—2
C8926Transesophageal echocardiography (tee) with contrast, or without contrast followed by with contrast, for congenital cardiac anomalies; including probe placement, image acquisition, interpretation and reportSpecial coverage instructions apply—2
C8927Transesophageal echocardiography (tee) with contrast, or without contrast followed by with contrast, for monitoring purposes, including probe placement, real time 2-dimensional image acquisition and interpretation leading to ongoing (continuous) assessment of (dynamically changing) cardiac pumping function and to therapeutic measures on an immediate time basisSpecial coverage instructions apply—2
G0340Image-guided robotic linear accelerator-based stereotactic radiosurgery, delivery including collimator changes and custom plugging, fractionated treatment, all lesions, per session, second through fifth sessions, maximum five sessions per course of treatmentCarrier judgment—1
G0339Image-guided robotic linear accelerator-based stereotactic radiosurgery, complete course of therapy in one session or first session of fractionated treatmentCarrier judgment—1
G0563Stereotactic body radiation therapy, treatment delivery, per fraction to 1 or more lesions, including image guidance and real-time positron emissions-based delivery adjustments to 1 or more lesions, entire course not to exceed 5 fractionsCarrier judgment—1
Q0512Pharmacy supply fee for oral anti-cancer, oral anti-emetic or immunosuppressive drug(s); for a subsequent prescription in a 30-day periodSpecial coverage instructions apply—2
Q0511Pharmacy supply fee for oral anti-cancer, oral anti-emetic or immunosuppressive drug(s); for the first prescription in a 30-day periodSpecial coverage instructions apply—2
J8999Prescription drug, oral, chemotherapeutic, nosSpecial coverage instructions apply—1
J8530Cyclophosphamide; oral, 25 mgSpecial coverage instructions apply—1
J8597Antiemetic drug, oral, not otherwise specifiedSpecial coverage instructions apply—1
J8610Methotrexate; oral, 2.5 mgSpecial coverage instructions apply—1
J8498Antiemetic drug, rectal/suppository, not otherwise specifiedSpecial coverage instructions apply—1
Q5110Injection, filgrastim-aafi, biosimilar, (nivestym), 1 microgramSpecial coverage instructions apply—1
Q5125Injection, filgrastim-ayow, biosimilar, (releuko), 1 microgramCarrier judgment—1
Q5101Injection, filgrastim-sndz, biosimilar, (zarxio), 1 microgramSpecial coverage instructions apply—1
J1442Injection, filgrastim (g-csf), excludes biosimilars, 1 microgramSpecial coverage instructions apply—1
J1449Injection, eflapegrastim-xnst, 0.1 mgCarrier judgment—1
J1447Injection, tbo-filgrastim, 1 microgramSpecial coverage instructions apply—1
Q5108Injection, pegfilgrastim-jmdb (fulphila), biosimilar, 0.5 mgCarrier judgment—1
Q5111Injection, pegfilgrastim-cbqv (udenyca), biosimilar, 0.5 mgCarrier judgment—1
Q5127Injection, pegfilgrastim-fpgk (stimufend), biosimilar, 0.5 mgCarrier judgment—1
J2506Injection, pegfilgrastim, excludes biosimilar, 0.5 mgCarrier judgment—1
Q5122Injection, pegfilgrastim-apgf (nyvepria), biosimilar, 0.5 mgCarrier judgment—1
Q5130Injection, pegfilgrastim-pbbk (fylnetra), biosimilar, 0.5 mgCarrier judgment—1

39 more codes are listed. See every code with payment by region in Caduvo.

Medicare policy articles listing C79.9

A diagnosis listed as covered in a billing and coding article supports medical necessity for the article's codes; it does not guarantee payment. Coverage depends on the LCD's criteria, the contractor's jurisdiction and documentation in the medical record.

Other C79 diagnoses (Secondary malignant neoplasm of other and unspecified sites)

Frequently asked questions

Does Medicare cover C79.9 (Secondary malignant neoplasm of unspecified site)?

Medicare covers items and services, not diagnoses. 7 Medicare billing and coding articles list C79.9 as a covered diagnosis for 64 HCPCS Level II codes: the diagnosis can support medical necessity for those codes, but payment still depends on the LCD's coverage criteria and the medical record.

Which HCPCS codes can be billed with ICD-10 C79.9?

The Level II codes from the policies most specific to this diagnosis are C8925 (Transesophageal echocardiography (tee) with contrast, or…, 2 articles); C8926 (Transesophageal echocardiography (tee) with contrast, or…, 2 articles); C8927 (Transesophageal echocardiography (tee) with contrast, or…, 2 articles); G0340 (Image-guided robotic linear accelerator-based stereotactic…, 1 article); G0339 (Image-guided robotic linear accelerator-based stereotactic…, 1 article). Code choice depends on the item supplied; check each code's descriptor.

Which Medicare policy articles list C79.9?

A56874 (Billing and Coding: Stereotactic Radiation Therapy: Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT)); A56809 (Billing and Coding: Transesophageal Echocardiography (TEE)); A52868 (Billing and Coding: Transesophageal Echocardiography (TEE)), and 4 more articles.

What is ICD-10-CM code C79.9?

C79.9 is the ICD-10-CM code for secondary malignant neoplasm of unspecified site, in category C79 (Secondary malignant neoplasm of other and unspecified sites), chapter 2: Neoplasms.

Next steps

Sources: CMS Medicare Coverage Database billing and coding articles (covered ICD-10 code lists and HCPCS links); ICD-10-CM FY2026; CMS HCPCS Level II release October 2026; CMS DMEPOS fee schedule 2026 (non-rural state fees). Not billing or legal advice.

Chapter 2: Neoplasms · All diagnoses · HCPCS lookup