Rule 26(a)(2)(B) Expert Report Checklist
Six requirements, quoted in the rule's own words, so you can read the report on your desk against the rule rather than against somebody's paraphrase of it. Then eighteen practice points, counted separately — because the rule imposes six, and a page that runs the two together has made both harder to argue about.
- THE RULE
- 6 requirements, quoted
- PRACTICE
- 18 points, counted apart
- APPLIES TO
- Retained testifying experts
- FORMAT
- HTML · print · Save as PDF
- GATING
- None · no email required
- ADVICE
- Not legal advice
Fed. R. Civ. P. 26(a)(2)(B) requires a retained expert’s report to contain six things: all opinions with their basis and reasons; the facts or data considered; the exhibits that will summarise or support the opinions; qualifications with a ten-year publication list; a four-year list of cases in which the witness testified at trial or by deposition; and a statement of compensation. Everything else a good report contains is practice, not rule.
This is an educational template, not legal advice
The language on this page is generic drafting, published to be read and understood. No court has approved it, it is not this firm’s filed language in any matter, and it has not been accepted or rejected in any specific proceeding. Nothing here is tailored to your case, your forum, or the order that governs your matter, and using it unadapted is the error the page exists to help you avoid.
Whether a particular omission matters in a particular matter — and what to do about it — depends on the forum, the scheduling order, the prejudice, and the explanation. This page tells you what the rule says and what a complete digital forensic report normally contains. It does not tell you whether to move on anything.
Reading it creates no attorney–client relationship and no expert-engagement relationship. Check the rules, standing orders, local practice and case law of your own forum before relying on any of it.
Six requirements, counted honestly
The rule imposes six things. It does not impose twenty-four. The difference is the whole discipline of this page.
Checklists for expert reports circulate with anywhere from six to forty items, and most of them mix the words of the rule with the author’s view of good practice without saying which is which. That is a problem in both directions. A litigator who treats a practice norm as a requirement makes an argument the rule does not support; a litigator who treats the whole list as optional misses the six things that are not.
So the six are quoted below in the rule’s own words, exactly as it words them, and each is followed by what it asks for, how it is most often failed in a digital forensic report, and its practice points — which are numbered in their own sequence, P1 through P18, and are not requirements of the rule. A report can satisfy all six and fail several practice points. A report can satisfy all 18 practice points and still be incomplete under the rule.
The same distinction is drawn by the interactive Rule 26 completeness check, which flags the checks that go beyond the literal text so the two can never be confused in a readout. This page is the printable form of the same discipline.
The six requirements
(i)All opinions, with basis and reasons
The report must contain … a complete statement of all opinions the witness will express and the basis and reasons for them.
What it asks for. Every opinion the witness intends to give at trial, with the reasoning that gets from the evidence to each one. “Complete” is the operative word: an opinion that is not in the report is an opinion that has not been disclosed.
How it is failed in a forensic report. A findings section that states conclusions and omits the intermediate steps — which artifact, parsed by which tool, produced which value, and why that value supports this conclusion rather than a competing one. The reasoning stays in the examiner's notes and never reaches the report.
- P1Each opinion is separately identifiable — numbered or headed — rather than left to be inferred from a narrative.
- P2Each opinion traces to the specific artifact, file, or log entry it rests on, not to the examination as a whole.
- P3The tool and version behind each value are stated, so a competent examiner with the same source material could re-run the work.
(ii)The facts or data considered
The report must contain … the facts or data considered by the witness in forming them.
What it asks for. Everything the witness considered, not only what they relied on. The 2010 amendment narrowed the disclosure from “data or other information” to “facts or data” to protect theories and mental impressions — not to shrink the factual disclosure.
How it is failed in a forensic report. An evidence inventory listing the images actually examined, omitting the material collected and set aside, the sources requested and never produced, and the transcripts, declarations or attorney summaries the examiner read before forming a view.
- P4Every item examined is identified individually — device, custodian, acquisition date, and an identifier tying it to the custody record.
- P5Material considered but not relied on is disclosed, including anything counsel supplied that the witness read before forming an opinion.
- P6Evidence that was requested, expected, or would ordinarily exist and was unavailable is identified as such rather than passing unmentioned.
(iii)Exhibits that summarise or support
The report must contain … any exhibits that will be used to summarize or support them.
What it asks for. The demonstratives and evidentiary exhibits the witness will use — timelines, artifact tables, extracted file listings, screen captures, hash schedules. Not a promise to prepare exhibits later.
How it is failed in a forensic report. “Demonstratives to be prepared” standing in for exhibits, or a table in the report later replaced at trial by a differently constructed version whose underlying query nobody disclosed.
- P7The exhibits are attached or served with the report rather than described as forthcoming.
- P8For any table, timeline or chart derived from data, the source and the method of derivation are stated well enough to be reproduced.
- P9Each exhibit is keyed to the opinion it supports, so an exhibit cannot arrive at trial attached to a different proposition.
(iv)Qualifications and the 10-year publication list
The report must contain … the witness's qualifications, including a list of all publications authored in the previous 10 years.
What it asks for. Qualifications for the question actually being answered, plus every publication authored in the previous ten years. The publication list is a fixed ten-year window, not a selection of relevant highlights.
How it is failed in a forensic report. A CV listing roles held and certifications acquired rather than examinations personally performed, and a publication list curated down to the flattering entries.
- P10The qualifications relate to the specific discipline the opinions require, not to digital forensics as a general field.
- P11The publication list covers the full ten years and says expressly that there are none where that is the case.
- P12Certifications carry their current status and date, rather than being listed as though a lapsed credential were current.
(v)The four-year testimony list
The report must contain … a list of all other cases in which, during the previous 4 years, the witness testified as an expert at trial or by deposition.
What it asks for. Every case in which the witness testified as an expert at trial or by deposition in the previous four years. Testified — so a matter in which a report was served and no testimony given falls outside the clause.
How it is failed in a forensic report. A list of captions and nothing else, or one that quietly omits the matters where the testimony went badly. Courts and case numbers are what make a list usable, and a list you cannot pull a docket from has not really been given.
- P13The list covers the full four years and identifies each matter well enough to locate the docket — caption, court, and case number.
- P14The nature of the testimony is identified, at minimum trial or deposition, and the retaining party is stated.
- P15Any prior ruling excluding or limiting this witness's testimony is disclosed rather than left in a docket for the other side to find.
(vi)The statement of compensation
The report must contain … a statement of the compensation to be paid for the study and testimony in the case.
What it asks for. What the witness is being paid for the work and the testimony in this case. A rate is the usual form; the clause asks about compensation in the case, not about a published rate card.
How it is failed in a forensic report. A single hourly figure with no indication of what else is billed — testimony and deposition at a different rate, travel, and the work of associates and technicians under the named expert's supervision.
- P16Rates are given for each category of work actually billed, including deposition and trial testimony where those differ.
- P17Work performed by anyone other than the named witness — associates, technicians, laboratory staff — is identified with its rate.
- P18The statement makes clear that no part of the compensation depends on the outcome of the matter or on the content of the opinion.
Quoted from Fed. R. Civ. P. 26(a)(2)(B) as in force in 2026. This subdivision was last substantively amended in 2010.
Which experts this applies to
The written-report requirement reaches a witness retained or specially employed to provide expert testimony, and a witness whose duties as the party’s own employee regularly involve giving expert testimony. A witness outside that description is disclosed under Rule 26(a)(2)(C) with a summary of the facts and opinions rather than a report.
The distinction matters more in digital forensics than in most disciplines, because the examiner who handled the incident is often an employee or an incident-response vendor who was working long before litigation was contemplated. Whether that person is a retained expert, a non-retained expert, or a fact witness about what they did changes what has to be disclosed and what can be asked.
| POSTURE | WHAT GETS DISCLOSED | THE PRACTICAL DIFFERENCE |
|---|---|---|
| Retained testifying expert | A written report containing all six elements | The four corners of the report bound the opinions available at trial |
| Employee whose duties regularly involve expert testimony | A written report containing all six elements | Turns on the employee's regular duties, not on their expertise |
| Non-retained expert under (a)(2)(C) | A summary of the facts and opinions, not a report | No publication list, no testimony list, no compensation statement |
| Consulting expert, not testifying | Nothing, absent exceptional circumstances | Work product protection is the point of the role |
| Fact witness describing what they did | Ordinary fact discovery | May describe the acquisition; opinions are a different question |
Timing and supplementation
Absent a stipulation or order, disclosures are due when the court orders, and a rebuttal report intended solely to contradict or rebut another party’s disclosure is due within 30 days after that disclosure. In practice the scheduling order governs and usually differs, so the order’s dates are the ones to work from.
- Supplementation is for correction, not extension. A supplement adding an opinion the examiner could have reached at the time is the one most likely to draw a motion, and the argument arrives close to trial.
- A re-parsed artifact is a disclosure question. Source material is frequently re-run with a newer tool version, and a changed value in a supplement is not a clerical correction — it is a change in the basis for an opinion.
- The testimony list ages during the matter. A four-year list served eighteen months before trial is no longer a four-year list, and the matters that closed in the interval are the ones the other side is reading.
Reading a forensic report against the list
Elements (i) and (ii) are where a digital forensic report normally comes apart, and they fail together: an opinion stated without the intermediate values is also an opinion whose factual basis has not been fully disclosed. The test that catches both is whether a competent examiner, given the same source material and this report, could reproduce each value in it.
Element (v) is the one to read rather than file. What to look for in the list is set out in the CV and testimony history guide; what to do with a report once it is complete is the deposition outline. Where the issue is methodology rather than disclosure, the Daubert guide and the Daubert exposure check cover the Rule 702 question, and Daubert or Frye covers which standard your forum applies.
Questions counsel ask
How many things does Rule 26(a)(2)(B) require an expert report to contain?
Does every expert have to serve a written report?
What happens if an element is missing from an expert report?
Is a four-year testimony list of captions enough?
Do the practice points on this page have to be satisfied?
What this checklist does not do
- It does not tell you whether to move on anything. Whether an omission is material, whether it is curable, and what relief is available are questions about a matter and a forum. The checklist establishes what is missing, not what follows from that.
- A complete report is not a reliable one. All six elements can be satisfied by an examination with serious methodological problems. Completeness under Rule 26 and admissibility under Rule 702 are different questions with different answers.
- The practice points are not requirements. They are numbered separately and labelled separately for that reason. Arguing one as though the rule compelled it is the error this page is built to prevent.
- It reflects the Federal Rules, not your forum, and is not a substitute for reading the rule. Disclosure obligations and the treatment of non-retained experts vary by jurisdiction and standing order. The six quotations here are one subdivision; Rule 26 also carries the protections that make draft reports and most expert–counsel communications non-discoverable.
Every element on this list is one a retained testifying expert has to produce in any event, and the four-year testimony list is the one worth asking for before retention rather than after. Conflicts come first.
A conflicts check and scoping call follow, normally within one business day. Please do not send privileged or case-sensitive material until conflicts have cleared.
Other resources
- RESOURCE 01 / PRESERVATIONEvidence Preservation Letter
A generic preservation letter, clause by clause, with each clause paired against what it actually preserves and what it leaves exposed. The annotation is the product.
- RESOURCE 02 / DEPOSITIONForensic Expert Deposition Outline
A topic-organised question outline for the deposition of an opposing digital forensics expert — qualifications, scope, tool validation, reproducibility, timestamps, custody, and what they were never asked to do.
- RESOURCE 04 / CUSTODYChain of Custody Form
A blank, printable custody form, plus a field guide explaining why each field exists and what a gap in it costs when the custody record is put to a witness.
- RESOURCE 05 / PROTECTIVE ORDERSource Code Inspection Protocol
Model protective-order terms for source code review, each paired with the failure mode it prevents — including the two terms that are routinely omitted and routinely fought over later.
- RESOURCE 06 / DILIGENCEExpert CV Red Flags
How to read a digital forensic expert's CV and testimony list for what they do not say — roles in place of examinations, curated publication lists, and what a missing four-year list means.
Attorney advertising / expert services. This page publishes an educational template and general information about forensic practice and the procedural rules that govern expert evidence. It is not legal advice, it does not create an attorney–client or expert-engagement relationship, and it is not a substitute for checking the rules, standing orders, and case law of your own forum. Prior results do not guarantee a similar outcome.