ABOS Board Certification Guide: Part I, Part II and KSB

The American Board of Orthopaedic Surgery (ABOS) certifies orthopaedic surgeons in the United States through a sequence that starts in residency and does not finish until about three years into practice. You participate in the ABOS Knowledge, Skills, and Behavior (KSB) Program throughout residency, sit the Part I written examination in the July after you graduate, then sit the Part II oral examination once you have built a practice and submitted a six-month case list. Pass Part II and you are an ABOS Diplomate with a 10-year certificate. This guide sets out each stage with the current rules and dates from abos.org (opens in a new tab). For a revision plan for the written paper, see how to prepare for ABOS Part I.

How does ABOS certification work?

The ABOS reserves the right to change its Rules and Procedures (opens in a new tab) without notice, and some older pages on its site carry superseded dates. Always work from the current calendar for your examination year.

The KSB Program: what residents must complete

The ABOS KSB Program (opens in a new tab) is a condition of entry to Part I. Every resident in an ACGME-accredited orthopaedic programme who intends to certify must take part. It has three strands:

• Orthopaedic knowledge: the AAOS Orthopaedic In-Training Examination (OITE), which shares a blueprint with Part I.
• Surgical skills: the resident requests an assessment of a specific case from a faculty member, who completes a 10-question form with free-text feedback.
• Professional behaviour: the resident requests an end-of-rotation behaviour assessment (five questions plus free text) from faculty. A yearly programme-level 360-degree assessment is also available but is separate from the count.

Assessments are requested through the ABOS KSB+ app or web portal, built with the ACGME so that the same entry also sends the case to the resident's ACGME case log.

The requirement is being phased in, according to the ABOS KSB participation requirements (opens in a new tab):

The full requirement for PGY-2 to PGY-5 is at least 80 skills and 6 behaviour assessments each year; PGY-1 residents need 12 skills and 3 behaviour assessments. The ABOS KSB FAQs (opens in a new tab) recommend spreading assessments evenly rather than loading one year, and say deficits from PGY-2 to PGY-4 should be made up the following year. Residency and KSB participation must both be complete by 30 June of the examination year. A graduate who falls short may reapply the next year after completing the assessments during fellowship or the first year in practice. There is no fee to residents or programmes.

ABOS Part I: format, dates and eligibility

ABOS Part I (opens in a new tab) tests general orthopaedics, basic science and the use of both in diagnosis and treatment. About 900 candidates sit it each summer.

Format. The examination has 328 items: six blocks of 52 questions (75 minutes each) and one block of 16 (30 minutes). The appointment lasts 9 hours: 8 hours of testing, 40 minutes of break time to use between sections as you choose, and a 20-minute tutorial. If you complete the tutorial at home, that time is added to your breaks (timing sheet (opens in a new tab)).

Eligibility. You must be in the fifth year of an ACGME-accredited orthopaedic residency, or have completed one, and the final 24 months must be in a single programme. Surgeons trained outside the US and Canada who hold full-time faculty posts at ACGME institutions may qualify through an alternate pathway (opens in a new tab).

Dates for the 2027 examination (Part I calendar (opens in a new tab)):

• Applications open on the ABOS Dashboard: 30 September 2026
• Application deadline: 1 December 2026, 4 pm ET (late deadline 15 December)
• Accommodation and alternate-date requests: 1 March 2027
• Scheduling opens: 1 April 2027
• Examination: 15 July 2027 at Pearson testing centres
• Alternate date for approved life events: 18 August 2027
• Results on the ABOS Dashboard: 3 September 2027

The combined application and examination fee is $1,240**, with a **$750 late fee (fees (opens in a new tab)).

Blueprint. The 2025 Part I blueprint (opens in a new tab) weights the six content domains as follows. Score reports give performance by the same domains.

The ABOS also publishes a subspecialty version of the same blueprint, organised by adult reconstruction, trauma, sports medicine and so on.

OITE linking. The ABOS and AAOS place shared items on both examinations to estimate the OITE score that corresponds to the minimum Part I pass. The 2025 linking study (opens in a new tab) put that at 182 items, or 69% correct, on the 2024 OITE. The ABOS describes this as a rough benchmark, not a prediction of your result.

Board eligibility and its five-year limit

Once you pass Part I you are board eligible. You have five years to pass Part II; if you do not, you must retake and pass Part I before you can sit Part II again. Time spent in fellowship after Part I does not count against the five years, provided each fellowship lasts at least six months.

When can you sit ABOS Part II?

The Part II oral examination (opens in a new tab) assesses clinical competence through your own practice. About 800 candidates sit it each July. To be admitted you need:

• A Part I pass within five years, excluding fellowship time.
• A full and unrestricted licence to practise in the United States or Canada, or full-time practice with the federal government.
• Practice start and privileges by 1 November, 20 months before the examination. For the July 2027 oral, that date was 1 November 2025.
• 17 consecutive full calendar months of operative practice in one location, other than as a resident or fellow, running from that 1 November to 31 March of the examination year.

If you change practice location, association or hospital privileges within those 17 months, you must tell the ABOS. The Credentials Committee may defer you by a year so the new practice can settle (Part II FAQ (opens in a new tab)).

Part II timeline for the 2027 examination

From the Part II calendar (opens in a new tab) and the ABOS case list information packet:

Some ABOS pages still give 15 August as the main deadline, which was the date in earlier cycles. The 2027 calendar and packet both say 1 August. Fees are a $1,175** application and credentialing fee, a **$1,550 examination fee and a $750 late fee (Part II fees (opens in a new tab)).

Building your ABOS case list

The case list is the core of Part II. The ABOS uses it in four ways: to choose the 12 cases you will present, to screen for outliers (which veteran surgeons review further and may refer to the Credentials Committee), to send you a feedback report comparing your practice with peers in your subspecialty, and to prompt your own reflection (case lists (opens in a new tab)).

What goes on the list

You enter every consecutive operative case in which you were the primary surgeon, at every hospital and surgery centre where you operate, from 1 January to 30 June of the year before the oral. That includes same-day surgery. A return to theatre for a complication is entered as a new case. Co-surgeon and assistant cases are excluded, with one exception: if you were the only orthopaedic surgeon in a co-surgeon case and dictated an independent operative note, it must be included.

To count, a case needs an incision and some form of anaesthetic. Fracture care without definitive skeletal fixation, percutaneous needling and manipulation under anaesthesia do not qualify, and the ABOS keeps a list of procedures not to include (opens in a new tab). The first CPT code you enter for a case must not be on that list.

Fields for each case

Cases are entered in the ABOS Scribe case list system, reached from your ABOS Dashboard (case list instructions (opens in a new tab)). Every required field must be complete before the list can be finalised:

• Patient initials, and the hospital medical record number (not your clinic number), so the medical records director can cross-check
• Age at surgery, sex and date of surgery
• ICD-10 diagnosis codes and CPT procedure codes, primary first
• Anatomic region, and the date you last physically saw the patient
• A description of the operation in 100 characters or fewer, with no history or identifiers
• Anaesthetic, surgical/technical and medical/systemic complications, each graded for severity and, for the last two, explained
• Any unexpected reoperation or readmission within 90 days, with an explanation

Patient-reported outcomes

For patients aged 12 and over you must enter an email address pre- or perioperatively unless the patient opts out. The ABOS emails PROMIS Physical Function and Pain Interference surveys at registration and at about 6 and 12 months. Patients do not see their results, and you receive only an aggregate report. A candidate with a large number of opt-outs may be reviewed by the Credentials Committee (patient-reported outcomes (opens in a new tab)).

Absences and gaps

If you are away from practice for 14 or more consecutive days during collection, the start of the period moves back from 1 January to 1 December. Contact the ABOS if you are out of surgical practice for more than 30 consecutive days, and expect to explain any 30-day gap between cases.

Verification and submission

Once every case is complete you finalise the list. This locks it for all facilities at once; reopening it means contacting the ABOS well before the deadline. You then download a signature page for each facility. The medical records director verifies that the list contains all your consecutive primary-surgeon cases there and signs, you countersign, and you upload the signed PDF for each facility. A facility where you hold privileges but did not operate needs a dated, signed letter on letterhead confirming no cases. When you upload records for your selected cases, they must either be de-identified to HIPAA standards or covered by written patient consent.

Practical advice

• Register patients at the time of surgery. The ABOS asks for registration pre- or perioperatively, and you can give the registration login to your schedulers. Reconstructing six months from memory in July invites errors and missed cases.
• Code carefully. Check that the primary CPT code reflects the operation you performed and is not on the exclusion list.
• Update follow-up at the end of June. Return to each case to record complications, reoperations and readmissions before you finalise.
• Book medical records early. Verification can take several days per facility. The ABOS asks candidates not to delay finalising while waiting for late-June follow-up, so the signatures do not make the application late.
• Record every complication. The list is consecutive and verified against hospital records, so omissions are detectable, and examiners assess how you recognised and managed problems. The ABOS packet states plainly that it is critical to include all complications.

Peer review

The Part II application asks for the names and email addresses of ABOS Diplomates and others in your geographical area who know your work. Each receives a 14-question survey on the six competency areas, scored on a four-point scale. The ABOS also emails Diplomates practising near you, identified by zip code. According to the ABOS, 98% of applicants meet its peer review criteria without referral to the Credentials Committee (peer review (opens in a new tab)). Check the email addresses you submit; the forms go to exactly those addresses.

What happens on Part II examination day?

The oral is held at the Palmer House in Chicago. It runs as four 30-minute sessions, each with two examiners and a 5-minute break between sessions. In each session you present 3 of your 12 selected cases, so 8 examiners see you over the day. Examiners ask about the cases you present and about your case list as a whole.

Each case is scored with the published scoring rubric (opens in a new tab) on nine facets, each from 0 (unacceptable) to 3 (above expected level):

1. Data gathering
2. Diagnosis and interpretive skills
3. Treatment plan
4. Surgical indications
5. Technical skill
6. Surgical complications
7. Outcomes
8. Ethics and professionalism
9. Applied knowledge

That gives 216 scores per candidate. The ABOS adjusts them for the severity or leniency of your examiners, the difficulty of each case and the difficulty of each skill. A psychometrician helps set the cut score, and there is no fixed percentage who pass. Candidates who are unsuccessful must submit a new application and a new case list for the following year.

Defending your own cases

The questions are about decisions you made, so preparation means knowing each of the 12 patients in detail: the history and examination you recorded, the imaging, why surgery was indicated, why you chose that implant and approach over the alternatives, your thromboprophylaxis and rehabilitation, and the outcome at last follow-up.

A clear structure helps. State the problem in one sentence, then the indication, the operation and the result. If there was a complication, say what happened, why you think it happened, how you managed it and what you now do differently. Do not blame the patient, the equipment or colleagues. If an examiner interrupts, stop and answer the new question; an interruption usually means they want a specific detail. Rehearse aloud with colleagues who have already passed, and use structured practice such as our guide to passing the orthopaedic viva and ABOS case-defence orals. For the day itself, see what to expect on orthopaedic exam day.

ABOS pass rates

The ABOS publishes results for Part I (opens in a new tab) and Part II (opens in a new tab).

Part II results for 2020 and 2021 were reported together because of the pandemic: 92% of 1,494 candidates passed. The 2026 Part I first-time pass rate was 10–11 percentage points lower than in 2022–2025; the ABOS statistics page gives no reason.

After certification: Continuing Certification

Diplomates receive a certificate valid for 10 years and may use the designation ABOSD. In 2026 the ABOS renamed Maintenance of Certification (MOC) as Continuing Certification (CC). The CC Program (opens in a new tab) has four parts:

1. Professional standing: peer review, a full and unrestricted licence in every jurisdiction where you hold one, and hospital credentials.
2. Lifelong learning and self-assessment: 240 Category 1 CME credits, including at least 40 self-assessment examination (SAE) credits, over the cycle. Diplomates whose certificate expires in 2031 or later must earn 120 credits (20 SAE) in years 1–5 and another 120 (20 SAE) in years 6–10.
3. Cognitive expertise: one of three knowledge assessments (below).
4. Performance in practice: a Professional Standing Update and case list in year 7, 8 or 9, with peer review.

The knowledge assessment can be met in three ways (examination options (opens in a new tab)):

• Computer-based examination: 150 multiple-choice questions in 3 hours at a Pearson VUE centre, either general orthopaedics or a practice-profiled subspecialty paper, taken in years 5–10. The ABOS is phasing out several practice-profiled papers because so few Diplomates now take them.
• Oral recertification examination: the same format as Part II, 12 cases from your case list over four 30-minute sessions, held each July.
• ABOS Web-Based Longitudinal Assessment (ABOS WLA) (opens in a new tab): each January the ABOS posts more than 200 knowledge sources (articles, guidelines and appropriate use criteria). You choose 14 and the ABOS sets a 15th. In the spring window (3 April to 22 May in 2026) you answer 30 open-book questions, two per source, with 3 minutes per question. Answering at least 24 correctly earns a Quality Year, and you need five Quality Years by the end of year 8. The fee is $260 a year ($340 from April 2027).

The ABOS also awards subspecialty certificates in Surgery of the Hand and Orthopaedic Sports Medicine, each with its own examination and case list. Diplomates holding one can recertify both certificates together through the WLA by choosing at least five knowledge sources in the subspecialty each year.

Planning the whole pathway

The certification years overlap with the busiest part of a career: final-year residency, fellowship and starting a practice. Most of the risk sits in administration rather than knowledge: missing KSB numbers by 30 June, a late Part I application in December, a practice move that breaks the 17-month rule, or an incomplete case list in August. Put the calendar dates in your diary as soon as the ABOS publishes them. For how ABOS compares with the FRCS, FRACS, EBOT and other board examinations, see the global orthopaedic board exam atlas.