Onco-Nephrology Fellowship

What Is Onco-Nephrology?

Onco-nephrology sits at the intersection of two disciplines that increasingly share patients. As systemic cancer therapies have grown more potent and more nephrotoxic, and as patients with chronic kidney disease are surviving long enough to develop malignancies, the clinical overlap has become too large for either specialty to manage alone.

The subspecialty's core concerns include:

• Acute kidney injury in oncology patients — from tumor lysis syndrome, sepsis, volume depletion, obstruction, and direct tumor infiltration
• Chemotherapy nephrotoxicity — cisplatin and carboplatin, ifosfamide, high-dose methotrexate, and targeted agents including VEGF inhibitors and mTOR inhibitors each carry distinct renal risk profiles
• Immunotherapy-related nephritis — checkpoint inhibitor-associated acute tubulointerstitial nephritis has become one of the most clinically urgent problems in the field, requiring biopsy-informed decisions about whether to hold or resume therapy
• Paraneoplastic and cancer-associated glomerulonephritis — membranous nephropathy associated with solid tumors, minimal change disease with lymphoma, amyloidosis with plasma cell dyscrasias
• Electrolyte and metabolic disorders — SIADH, hypercalcemia of malignancy, tumor-induced Fanconi syndrome
• Renal supportive care in oncology — the appropriateness, timing, and goals of renal replacement therapy in patients with advanced cancer, a domain that involves palliative medicine as much as nephrology

A trained onco-nephrologist is not simply a general nephrologist who accepts oncology consults. The subspecialist brings interpretive fluency in oncology pharmacology, familiarity with trial protocols that have renal endpoints, and the clinical credibility to engage oncology teams as a peer rather than a consultant from another department.

Accreditation Status

State this plainly: onco-nephrology fellowships are not ACGME-accredited as of 2025. There is no standard curriculum, no minimum case log requirement, no accreditation site visit, and no certifying board examination. Every program that exists is an institution-sponsored advanced training position — structurally more like a research fellowship or a post-fellowship clinical appointment than a formal GME training program.

This has several practical consequences you should understand before applying:

• No portability guarantee. The credential you leave with is the reputation of the institution, the productivity of your research output, and the strength of your mentorship network — not a certificate that carries standardized meaning.
• No board exam. You cannot sit for an "onco-nephrology boards" because none exist. Academic positioning depends on publication record, clinical reputation, and institutional affiliation.
• Programs vary substantially. One program's onco-nephrology fellowship may emphasize inpatient consult volume; another may be structured primarily as a research fellowship with protected laboratory or clinical research time. You must interrogate each program individually.
• No centralized match. Application is direct, uncoordinated, and relationship-mediated. The processes described below are generalizations; individual programs diverge.

None of this disqualifies onco-nephrology as a career pathway. It does mean that applicants must do substantially more due diligence than they would for an ACGME-accredited fellowship, and that the value of the training is directly proportional to the quality of the program's clinical and research infrastructure.

Program Landscape

The number of active, identifiable onco-nephrology fellowship positions in the United States is small — estimates in the subspecialty literature and ASN forum discussions have placed the figure in the range of roughly five to ten programs, though this shifts as institutions start or pause positions. Because there is no accrediting body tracking these programs, no authoritative public registry exists. The landscape is best described as nascent and unevenly distributed.

Programs tend to cluster at:

• NCI-designated comprehensive cancer centers — where the oncology volume, trial infrastructure, and research funding create conditions in which an onco-nephrology service can function at scale
• Large academic nephrology divisions with a faculty member whose primary research or clinical focus is onco-nephrology — at many institutions, the fellowship exists because one or two faculty built it, and its continuity depends on their continued presence

Institutions that have been publicly associated with onco-nephrology training or active onco-nephrology programs in the subspecialty literature and society meeting programs include Memorial Sloan Kettering Cancer Center, MD Anderson Cancer Center, and academic nephrology divisions at several large university health systems. This list is not exhaustive and reflects programs that have had documented public presence; it does not confirm current fellowship availability. Verify directly with each institution's nephrology division before the application cycle.

The honest picture: if you are committed to this subspecialty, you are likely to be in contact with most of the active fellowship directors in the country within a few months of targeted outreach. The community is small enough that it is navigable by a motivated applicant.

Training Structure and Duration

Most onco-nephrology fellowships run for one year. A minority of programs, particularly those with a substantial research component or that are structured around an NIH research training grant, extend to two years. The two-year format is more common when the second year is primarily protected research time rather than additional clinical rotations.

A typical one-year structure includes some combination of:

• Inpatient onco-nephrology consult service — the clinical core of training; fellows manage AKI, evaluate new-onset proteinuria in patients on immunotherapy, interpret kidney biopsies in context, and advise on renal dosing adjustments for chemotherapy regimens
• Outpatient nephrology clinic — longitudinal management of CKD in cancer survivors, post-transplant patients with malignancy, and patients with cancer-associated glomerular disease
• Oncology service exposure — rotations on medical oncology, hematology, or BMT services to build fluency in the cancer treatment context in which renal problems arise
• Kidney biopsy conference and renal pathology — developing interpretive skills in cancer-associated glomerular and tubular pathology
• Dedicated research time — nearly all programs expect fellows to generate at least one manuscript-ready project during the training period; the research may be clinical epidemiology, translational, or outcomes-focused

Research expectations are not optional in any program worth considering. The career pathway for an onco-nephrology-trained physician is academic, and academic hiring committees evaluate publication trajectory. A fellowship year without a clear scholarly output is a missed opportunity that is difficult to recover from at the early career stage.

Prerequisites and Eligibility

The near-universal baseline requirement is completion of an ACGME-accredited nephrology fellowship. Onco-nephrology training assumes you have already acquired the full nephrology skill set — you are adding oncology-specific fluency and research productivity on top of that foundation, not building renal expertise from scratch.

Board eligibility or board certification in nephrology is expected by most programs, though the specific requirement varies. Candidates who are still within the eligibility window but have not yet sat for the ABIM nephrology examination are generally competitive; programs understand the timing constraints.

A minority of programs have accepted applicants with a background in medical oncology or hematology rather than nephrology, particularly for research-focused positions where the primary project involves renal endpoints in oncology trials. These positions are uncommon and typically require a strong research alignment with the program's existing work. If your background is in oncology rather than nephrology, expect to have a specific and credible explanation for how your training prepares you to function clinically in a nephrology-centric role.

Some programs express preference for candidates who have already demonstrated onco-nephrology interest during their nephrology fellowship — through research projects, case reports, or rotation on an existing onco-nephrology service. This preference is not universal, but it is common enough that candidates who plan ahead during nephrology fellowship have a meaningful advantage.

Core Competencies Developed

By the end of a well-structured onco-nephrology fellowship, trainees should have developed:

• AKI evaluation and management in oncology patients — distinguishing pre-renal, intrinsic, and post-renal causes in the oncology context; recognizing tumor lysis syndrome early and managing it aggressively; calibrating the threshold for renal replacement therapy against prognosis and patient goals
• Checkpoint inhibitor nephrotoxicity — clinical recognition, biopsy indication and interpretation, immunosuppression decisions (corticosteroid initiation, dosing, taper), and the immunotherapy rechallenge decision in collaboration with oncology
• Chemotherapy renal risk management — cisplatin hydration protocols, methotrexate leucovorin rescue and urine alkalinization, renal dose adjustment calculations, and guidance on whether and how to proceed with nephrotoxic regimens in patients with pre-existing CKD
• Cancer-associated glomerulonephritis — the differential diagnosis and workup of new-onset proteinuria or hematuria in a cancer patient; understanding which malignancies associate with which glomerular lesions; coordinating treatment of the kidney disease with treatment of the underlying cancer
• Kidney biopsy interpretation in oncology context — working with renal pathology to distinguish drug-induced, paraneoplastic, and coincidental glomerular disease
• Electrolyte disorders in cancer — SIADH in small cell lung cancer, hypercalcemia of malignancy (PTHrP-mediated and other mechanisms), hypomagnesemia from EGFR inhibitors, Fanconi syndrome from ifosfamide or tenofovir
• Renal supportive care and goals of care — dialysis decisions in patients with advanced malignancy, including the evidence base (such as it is) for conservative non-dialytic kidney management in oncology patients near end of life
• Research methods in nephrology and oncology — trial design, renal endpoint definition, administrative data analysis, and the regulatory environment for studies in cancer patients with kidney disease

Research and Scholarly Activity

Onco-nephrology does not yet have an established evidence base proportionate to its clinical importance. That gap is both a challenge and an opportunity: fellows enter a field where rigorous work is genuinely needed and where early career contributions can have disproportionate impact on clinical practice.

Most programs have active research programs generating output in journals including the Clinical Journal of the American Society of Nephrology (CJASN), Kidney360, the Journal of Clinical Oncology (JCO), and subspecialty journals in hematology and oncology. Fellows are expected to contribute to at least one project that reaches submission-ready form by the end of training.

Common research domains in current onco-nephrology programs include:

• Incidence, risk factors, and outcomes of AKI in specific cancer populations using institutional registries or claims data
• Checkpoint inhibitor nephritis: natural history, biopsy findings, predictors of recovery, rechallenge outcomes
• Renal endpoints in oncology clinical trials — many trials were not designed to capture kidney outcomes in a meaningful way, and secondary analyses in this space have been productive
• Biomarker development for early detection of cancer therapy-associated nephrotoxicity
• Palliative nephrology and dialysis decision-making in oncology

If a program cannot clearly describe the research infrastructure — mentors with protected time, IRB-approved protocols, access to datasets — that is relevant information about whether the training year will produce the scholarly output your career requires.

Career Outcomes

The post-fellowship trajectory is almost exclusively academic. An onco-nephrology fellowship is not a path toward private practice or community nephrology. The training is designed to produce physician-scientists and clinician-educators who can build or sustain onco-nephrology programs at academic medical centers.

Typical landing points include:

• Faculty positions at NCI-designated cancer centers or academic nephrology divisions — usually at the instructor or assistant professor level, with an expectation of building an independent research program over the K-award or equivalent timeline
• Leadership roles within professional society onco-nephrology working groups — the ASN Onco-Nephrology Forum, ASCO kidney disease working groups, and international collaborative networks including the International Kidney and Cancer Research Consortium (IKCRC) and related organizations are where subspecialty norms are being established; fellowship-trained physicians are positioned to contribute early
• Clinical trial investigatorship — developing expertise in renal endpoint adjudication, serving as a nephrology co-investigator on oncology trials, or leading investigator-initiated trials with renal outcomes as primary endpoints

The field is sufficiently new that career trajectories are not yet as predictable as those in established subspecialties. That is an honest characterization, not a dissuasion. For the right applicant — someone who is genuinely motivated by building a clinical and research identity in a nascent field rather than joining an established pipeline — the ambiguity is generative rather than threatening.

How to Find and Apply

There is no centralized application system for onco-nephrology fellowships. No match. No shared portal. Applications are submitted directly to programs, and programs fill positions on independent timelines.

Practical steps:

• Identify active programs through society networks. The ASN Onco-Nephrology Forum is the most direct route. Attend ASN Kidney Week and find the onco-nephrology sessions — the faculty presenting there are often the same faculty running fellowship programs or who can direct you to those who are. ASCO Annual Meeting has onco-nephrology content and attendees from both disciplines.
• Make direct contact with program directors 12 to 18 months before your intended start date. Many positions are filled informally through relationships built at meetings or through shared mentors before any formal posting appears. Waiting for a job board listing is a strategy that puts you behind applicants who reached out directly.
• Use your nephrology fellowship mentors. If your fellowship program has any connection to onco-nephrology — a faculty member who collaborates with the subspecialty, a former trainee who moved in that direction — those contacts are the most direct path to introductions.
• Check institutional websites directly. Some programs post fellowship opportunities through their nephrology division or cancer center website without broad dissemination. A systematic search of division websites at NCI-designated cancer centers is worth the time.
• Be prepared for programs that have no current opening. In a field this small, the answer may be "we don't have a position this cycle but let's stay in touch." Maintaining those relationships is part of the application process.

Application Materials

In the absence of a standardized application, programs generally expect:

• Curriculum vitae — with particular attention to any prior onco-nephrology or oncology-adjacent work: relevant research projects, presentations, publications, or clinical rotations
• Personal statement — this document carries more weight here than in ACGME fellowship applications because program directors are evaluating whether your specific interests align with their research program; a generic statement is an immediate signal of insufficient program-specific preparation; articulate clearly why onco-nephrology, why this specific program, and what you intend to build during and after training
• Three letters of recommendation — ideally from faculty who span both disciplines: at least one from a nephrology mentor who can speak to your clinical skills and academic potential, and at least one from an oncology-adjacent mentor who can speak to your engagement with cancer medicine; a letter from an established onco-nephrologist who knows your work is highly valuable if you have made that connection
• Research summary or reprints — any prior publications, abstracts, or grant applications relevant to the subspecialty; if your prior work is not directly in onco-nephrology, a brief research summary contextualizing how it connects to your proposed trajectory is appropriate

Compensation and Funding

Compensation structures vary substantially because these are not ACGME-accredited positions and are not subject to standardized GME funding rules. Fellows are typically compensated at a level commensurate with their years of postgraduate training — roughly equivalent to upper-level nephrology fellow or junior faculty stipends — but the source and structure of that funding differ by program.

Some positions are funded through departmental or division training budgets. Others are supported by NIH training grants (T32 mechanisms), in which case stipend levels are set by NIH guidelines for the applicable year. A minority of positions are structured as junior faculty appointments with corresponding salary and benefits, which can affect subsequent employment negotiations.

Benefits — health insurance, malpractice coverage, CME allowance, leave — are institution-specific. Ask explicitly about all of these before accepting a position. Compensation transparency is reasonable to expect from any program serious about recruiting, and a program that is evasive about funding structure is giving you information worth weighing. See the site's data pages for general context on postgraduate compensation levels.

Professional Societies and Resources

• ASN Onco-Nephrology Forum — the primary professional home for onco-nephrologists within American nephrology; the Forum hosts programming at Kidney Week, maintains working groups, and is the best single entry point for networking and identifying unfilled fellowship positions
• American Society of Clinical Oncology (ASCO) — the major oncology society; relevant for its working groups that address kidney disease as a cancer complication and for its annual meeting, which draws the oncology faculty who collaborate with onco-nephrologists
• Kidney360 — the ASN's open-access journal, which has published a substantial volume of onco-nephrology case reports, reviews, and original research and is a useful index of the subspecialty's current literature
• CJASN and JASN — the flagship ASN journals; both publish onco-nephrology original research, and reviewing recent issues gives a realistic picture of the field's research questions and methodological standards
• International Kidney and Cancer Research Consortium (IKCRC) and related networks — multinational collaborative groups working on cancer and kidney disease; fellows who engage with these networks during training build international research connections that are valuable for career development

The onco-nephrology community is small enough that a motivated applicant who reads the literature, attends Kidney Week, and introduces themselves thoughtfully to the faculty presenting in onco-nephrology sessions will, within a year, have a working knowledge of who is doing what and where openings are likely to exist. This is not a field where passive application succeeds.

Frequently Asked Questions

Do I need to complete nephrology fellowship first?

For nearly all programs, yes. The assumption is that you arrive with full nephrology competency and are adding depth in oncology-specific disease management and research skills. The clinical volume and complexity at most onco-nephrology programs requires the ability to function independently as a nephrologist from day one of fellowship. A small number of programs have structured positions for applicants from medical oncology backgrounds, but those positions are the exception and typically require a specific research alignment rather than a general interest in the subspecialty.

Is there a board examination?

No. As of 2025, there is no certifying examination in onco-nephrology. Subspecialty recognition through a board process would require ACGME accreditation and ABIM certification pathway development, neither of which exists at this time. The field is actively discussing what subspecialty credentialing should look like, but that conversation has not yet produced a certification mechanism.

Can I pursue this after medical oncology or hematology training rather than nephrology?

Occasionally, and with caveats. Some programs have structured research fellowships open to oncology-trained physicians when the project is specifically renal-focused. These positions are rare. If you are an oncology-trained physician interested in onco-nephrology, the most direct path is identifying a specific research question, finding a program whose faculty work in that area, and framing your application around the research alignment rather than a general subspecialty interest. Expect that the clinical responsibilities of the position may be more limited than they would be for a nephrology-trained applicant, and be explicit about how you plan to manage the clinical knowledge gap.

What distinguishes onco-nephrology practice from standard nephrology?

Several things, in practice. The patient population is different: oncology patients have competing priorities, often abbreviated life expectancy, and treatment regimens that create renal risk on a timeline measured in days rather than months. The decision-making involves constant negotiation between oncologic benefit and renal risk — when to hold immunotherapy, whether to proceed with a nephrotoxic regimen in a patient with CKD, when dialysis serves the patient's goals and when it does not. The collaboration model is different: onco-nephrologists function as embedded members of oncology teams rather than consultants who are called and then disengage. And the research questions are different: the field is generating its own evidence base rather than applying established nephrology evidence to a new population. A general nephrologist who occasionally manages cancer patients is not practicing onco-nephrology in the subspecialty sense; the distinction is in the depth of oncology integration, the research orientation, and the systematic expertise in cancer therapy-associated kidney disease.

How competitive are positions?

The small number of positions relative to the growing number of nephrology fellows who express interest in the subspecialty means that competitive candidates are those with prior research output, a clear scholarly direction, and relationships with faculty in the field. Applying without prior engagement — no relevant research, no society involvement, no connections to the onco-nephrology community — is unlikely to be successful at the programs with the strongest infrastructure. Building the application during nephrology fellowship, not after, is the practical answer to this question.