100+ Free ABIM Infectious Disease Practice Questions

Pass your American Board of Internal Medicine Infectious Disease Subspecialty Certification exam on the first try — instant access, no signup required.

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Question 1

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A 42-year-old previously healthy woman presents as an outpatient with cough, fever, and a right lower lobe infiltrate on chest x-ray. She has no comorbidities, no recent antibiotic exposure, and no risk factors for drug-resistant pathogens. Per the ATS/IDSA 2019 community-acquired pneumonia guideline, which of the following is the preferred outpatient regimen?

Amoxicillin alone

Amoxicillin plus azithromycin, or doxycycline monotherapy

Levofloxacin plus vancomycin

Ceftriaxone plus azithromycin IV

to track

2026 Statistics

Key Facts: ABIM Infectious Disease Exam

~240

Exam Questions

ABIM 2026

~10 hours

Exam Day Length

ABIM 2026

~$2,990

Application + Exam Fee

ABIM 2026

~85-90%

First-Attempt Pass Rate

ABIM Assessment Results

2 years

ID Fellowship Required

ACGME

5-yr LKA

MOC Option

ABIM MOC

The ABIM Infectious Disease subspecialty exam certifies internists as consultative ID physicians. It contains approximately 240 single-best-answer multiple-choice questions administered across four ~2-hour modules on a single ~10-hour test day at Pearson VUE centers. The application + exam fee is approximately $2,990. Eligibility requires active ABIM Internal Medicine certification plus satisfactory completion of a 2-year ACGME-accredited Infectious Disease fellowship. The 2026 blueprint emphasizes evidence-based antimicrobial therapy anchored to IDSA/CDC guidelines — CAP with ATS/IDSA 2019, UTI per IDSA 2022, endocarditis with modified Duke criteria, C. difficile per IDSA 2021 (fidaxomicin first-line, bezlotoxumab or FMT for recurrence), HIV initial ART (BIC/TAF/FTC or DTG/ABC/3TC with HLA-B*5701), long-acting cabotegravir-rilpivirine, PrEP (TDF/FTC or cabotegravir-LA), PJP and MAC prophylaxis, tuberculosis (IGRA diagnosis, 3HP latent therapy, BPaL for MDR-TB), invasive candidiasis (echinocandin), cryptococcal meningitis (amp B + flucytosine), STIs (ceftriaxone 500 mg for gonorrhea, benzathine penicillin G for syphilis), multidrug-resistant organism treatment (ceftazidime-avibactam, meropenem-vaborbactam, cefiderocol), antimicrobial stewardship including penicillin allergy delabeling, the 2024 ACIP adult vaccine schedule (Shingrix, RSV ≥60, PCV20 or PCV15+PPSV23 ≥65), and infection prevention. Once certified, diplomates maintain certification via the Longitudinal Knowledge Assessment (LKA) or the 10-year recertification exam.

Sample ABIM Infectious Disease Practice Questions

Try these sample questions to test your ABIM Infectious Disease exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1A 42-year-old previously healthy woman presents as an outpatient with cough, fever, and a right lower lobe infiltrate on chest x-ray. She has no comorbidities, no recent antibiotic exposure, and no risk factors for drug-resistant pathogens. Per the ATS/IDSA 2019 community-acquired pneumonia guideline, which of the following is the preferred outpatient regimen?

A.Amoxicillin alone

B.Amoxicillin plus azithromycin, or doxycycline monotherapy

C.Levofloxacin plus vancomycin

D.Ceftriaxone plus azithromycin IV

Explanation: For healthy outpatient adults without comorbidities, ATS/IDSA 2019 recommends amoxicillin (1 g TID) plus a macrolide (typically azithromycin) OR doxycycline monotherapy. Macrolide monotherapy is recommended only when local pneumococcal macrolide resistance is <25%. Amoxicillin alone lacks atypical coverage. Fluoroquinolones are reserved for outpatients with comorbidities. IV ceftriaxone + azithromycin is the inpatient, non-severe regimen.

2A 68-year-old man with COPD and heart failure is admitted with severe community-acquired pneumonia. He has no prior isolation of MRSA or Pseudomonas and no recent hospitalization with IV antibiotics. Per ATS/IDSA 2019, which empiric regimen is most appropriate?

A.Ceftriaxone plus azithromycin (or respiratory fluoroquinolone)

B.Vancomycin plus cefepime plus azithromycin

C.Piperacillin-tazobactam plus linezolid plus levofloxacin

D.Ertapenem plus doxycycline

Explanation: For severe inpatient CAP without locally validated risk factors for MRSA or Pseudomonas, ATS/IDSA 2019 recommends β-lactam (ceftriaxone, cefotaxime, ampicillin-sulbactam, or ceftaroline) plus a macrolide, or a respiratory fluoroquinolone alone. Empiric MRSA and anti-pseudomonal coverage should be added only when there is prior respiratory isolation of these pathogens, hospitalization with parenteral antibiotics in the last 90 days, or locally validated risk factors (and de-escalated if cultures are negative).

3A 58-year-old woman is admitted to the ICU with ventilator-associated pneumonia on hospital day 9. Endotracheal culture grows Pseudomonas aeruginosa susceptible only to ceftolozane-tazobactam and aminoglycosides. Which of the following is the best definitive therapy?

A.Ceftolozane-tazobactam monotherapy

B.Tobramycin monotherapy

C.Ciprofloxacin plus amikacin

D.Meropenem alone

Explanation: For MDR Pseudomonas VAP susceptible to ceftolozane-tazobactam, monotherapy with ceftolozane-tazobactam is appropriate; IDSA/ATS 2016 HAP/VAP and subsequent IDSA MDR guidance supports β-lactam monotherapy once susceptibility is known. Aminoglycoside monotherapy has poor lung penetration and is not appropriate. Combination therapy with an aminoglycoside is used empirically or in select cases but is not required once susceptibility is established.

4A 28-year-old woman presents with dysuria, urinary frequency, and no fever or flank pain. She has no known drug allergies. Per IDSA 2022/updated uncomplicated UTI guidance, which of the following is a first-line option for acute uncomplicated cystitis?

A.Nitrofurantoin 100 mg BID × 5 days

B.Ciprofloxacin 500 mg BID × 7 days

C.Amoxicillin 500 mg TID × 7 days

D.Ceftriaxone 1 g IV × 1 dose

Explanation: First-line options for acute uncomplicated cystitis are nitrofurantoin 100 mg BID × 5 days, TMP-SMX DS BID × 3 days (if local E. coli resistance <20%), or fosfomycin 3 g PO × 1. Fluoroquinolones and β-lactams are second-line due to collateral damage (resistance selection, C. difficile, microbiome effects). Amoxicillin has high resistance. Ceftriaxone is for pyelonephritis, not cystitis.

5A 44-year-old woman presents with fever 39°C, flank pain, and dysuria. She is hemodynamically stable and can tolerate oral intake. Urine culture is pending. Which empiric outpatient regimen is appropriate for acute uncomplicated pyelonephritis?

A.Ciprofloxacin 500 mg BID × 7 days (or after an IV ceftriaxone 1 g loading dose if local fluoroquinolone resistance >10%)

B.Nitrofurantoin 100 mg BID × 5 days

C.Fosfomycin 3 g PO × 1 dose

D.Amoxicillin 500 mg TID × 14 days

Explanation: For acute uncomplicated pyelonephritis in outpatients, oral fluoroquinolone (ciprofloxacin 500 mg BID × 7 days or levofloxacin 750 mg daily × 5 days) is preferred; add an initial IV long-acting agent (ceftriaxone 1 g or aminoglycoside) if local E. coli fluoroquinolone resistance exceeds 10%. Oral β-lactams like amoxicillin-clavulanate are less effective. Nitrofurantoin and fosfomycin achieve inadequate renal tissue concentrations and are NOT used for pyelonephritis.

6A 62-year-old man with a bicuspid aortic valve presents with two weeks of fever and malaise. Two sets of blood cultures grow viridans group streptococci. TTE shows a 1.1 cm aortic valve vegetation. Per the modified Duke criteria, this case is best classified as:

A.Definite infective endocarditis

B.Possible infective endocarditis

C.Rejected infective endocarditis

D.Culture-negative endocarditis

Explanation: Modified Duke criteria classify IE as DEFINITE if 2 major criteria are met. Major criteria include (1) typical organism (viridans streptococci, Staph aureus, HACEK, etc.) in 2 separate blood cultures, and (2) evidence of endocardial involvement (vegetation, abscess, new regurgitation on echo). This patient meets both — definite IE. Possible IE requires 1 major + 1 minor or 3 minor criteria.

7A 34-year-old man who injects drugs intravenously presents with fever and dyspnea. Blood cultures grow methicillin-sensitive Staphylococcus aureus (MSSA). TTE shows a tricuspid valve vegetation without evidence of embolic complications, extracardiac infection, or persistent bacteremia. Which duration of IV therapy is appropriate?

A.2 weeks of nafcillin or cefazolin (short-course right-sided native valve IE)

B.6 weeks of vancomycin

C.4 weeks of daptomycin plus rifampin

D.12 weeks of ampicillin plus gentamicin

Explanation: Uncomplicated right-sided MSSA native-valve endocarditis in IVDU can be treated with 2 weeks of nafcillin or oxacillin (cefazolin acceptable) if there is no extracardiac infection, no hardware, rapid clearance of bacteremia, and no complications. For complicated right-sided IE, left-sided IE, or any MRSA IE, standard is 4-6 weeks of IV therapy. Vancomycin is used only for MRSA or true β-lactam allergy.

8A 70-year-old man has Staphylococcus aureus bacteremia from a presumed catheter source. The central line is removed and repeat cultures at 72 hours are negative. A TEE shows no vegetation or valvular pathology. The patient defervesces and has no metastatic foci. Which minimum duration of IV antibiotic therapy is appropriate?

A.14 days from the first negative blood culture

B.7 days

C.4 weeks

D.6 weeks

Explanation: For uncomplicated Staph aureus bacteremia (defined as: negative TEE, no metastatic infection, no implanted hardware, no persistent fever or bacteremia beyond 72 hours, and community-acquired catheter removal), the minimum duration is 14 days of IV therapy counted from the first negative blood culture. Complicated SAB (endocarditis, prosthetic material, metastatic infection, persistent bacteremia) requires 4-6 weeks. TEE is strongly preferred over TTE for exclusion given higher sensitivity for vegetations.

9A 72-year-old man with no prosthetic valve has enterococcal endocarditis caused by Enterococcus faecalis that is susceptible to ampicillin, penicillin, and gentamicin. His creatinine clearance is 35 mL/min. Which regimen is preferred to minimize nephrotoxicity?

A.Ampicillin plus ceftriaxone (AmpC regimen)

B.Ampicillin plus high-dose gentamicin

C.Vancomycin monotherapy

D.Daptomycin monotherapy

Explanation: For E. faecalis endocarditis, ampicillin + ceftriaxone (6 weeks) is an evidence-based alternative to ampicillin + gentamicin and is preferred when aminoglycoside nephrotoxicity is a concern (elderly, CKD, pre-existing renal dysfunction). It has equivalent efficacy with less nephrotoxicity. Ampicillin + gentamicin remains acceptable when creatinine clearance permits. Vancomycin and daptomycin are reserved for ampicillin-resistant strains or severe penicillin allergy.

10Which of the following organisms is included in the HACEK group associated with culture-negative or slow-growing endocarditis?

A.Haemophilus parainfluenzae

B.Helicobacter pylori

C.Hafnia alvei

D.Histoplasma capsulatum

Explanation: HACEK organisms are fastidious gram-negatives associated with native-valve endocarditis: Haemophilus spp. (H. parainfluenzae, H. aphrophilus), Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae. Modern automated blood culture systems typically detect HACEK within 5 days. Standard therapy is ceftriaxone 2 g IV daily × 4 weeks for native valve, 6 weeks for prosthetic valve.

About the ABIM Infectious Disease Exam

The ABIM Infectious Disease subspecialty exam certifies internists as consultative infectious disease physicians. The exam covers bacterial infections and antimicrobial therapy (CAP per ATS/IDSA 2019, UTI per IDSA 2022, endocarditis with modified Duke criteria, C. difficile per IDSA 2021), HIV and opportunistic infections, viral hepatitis, tuberculosis and NTM, fungal infections, parasitic and tropical disease, transplant and immunocompromised hosts, STIs (CDC 2021), antimicrobial stewardship and multidrug-resistant organisms, infection prevention, and the 2024 ACIP adult vaccine schedule.

Questions

240 scored questions

Time Limit

~10-hour exam day (four ~2-hour modules)

Passing Score

Criterion-referenced scaled score (pass/fail)

Exam Fee

~$2,990 application + exam fee (American Board of Internal Medicine (ABIM))

ABIM Infectious Disease Exam Content Outline

22%

Bacterial Infections & Antimicrobial Therapy

CAP (ATS/IDSA 2019), HAP/VAP, UTI (IDSA 2022), endocarditis (modified Duke, S. aureus bacteremia with TEE), SSTI, osteomyelitis, meningitis (empiric by age + dexamethasone), sepsis, C. difficile (IDSA 2021 — fidaxomicin, bezlotoxumab, FMT)

16%

HIV & Opportunistic Infections

HIV initial ART (BIC/TAF/FTC or DTG/ABC/3TC with HLA-B*5701), long-acting Cabenuva, PrEP/PEP, OIs by CD4 (PJP, MAC, CMV, toxoplasmosis, cryptococcus with amp B + flucytosine), IRIS, viral hepatitis HBV and HCV DAA therapy

10%

Mycobacterial Disease

Latent TB IGRA, latent treatment (9 mo INH, 4 mo rifampin, 3HP), active TB RIPE 2+4 regimen, TB-HIV coinfection, MDR/XDR-TB (BPaL — bedaquiline + pretomanid + linezolid), NTM MAC clarithromycin + ethambutol + rifampin, leprosy WHO MDT

10%

Viral Infections (non-HIV)

COVID-19 (remdesivir, dex, baricitinib, Paxlovid, molnupiravir), influenza (oseltamivir, baloxavir), RSV adults ≥60, Mpox (JYNNEOS, tecovirimat), HSV/VZV, EBV/CMV, BK virus in transplant, adenovirus

Fungal Infections

Candidemia (echinocandin first-line, step-down fluconazole, line removal, C. auris), aspergillosis (voriconazole/isavuconazole), cryptococcosis (amp B + flucytosine → fluconazole), endemic mycoses, mucormycosis (surgery + liposomal amp B + posaconazole/isavuconazole)

Transplant & Immunocompromised Host

Timing framework (<1 mo, 1-6 mo, >6 mo), CMV prophylaxis vs preemptive, PJP and VZV prophylaxis, antifungal prophylaxis (posaconazole in AML/HSCT), neutropenic fever (cefepime/pip-tazo/meropenem; add vancomycin for line infection or severe mucositis)

Sexually Transmitted Infections

CDC 2021 — gonorrhea (ceftriaxone 500 mg IM), chlamydia (doxycycline BID 7 d), syphilis staging and benzathine penicillin G dosing, neurosyphilis IV penicillin G, PID (ceftriaxone + doxycycline + metronidazole), HPV, HSV, trichomoniasis

Antimicrobial Stewardship & Resistance

ESBL, KPC, NDM carbapenemases, VRE, MDR Pseudomonas, CRE, carbapenem-sparing (ceftazidime-avibactam, meropenem-vaborbactam, cefiderocol, eravacycline, plazomicin, ceftolozane-tazobactam). Stewardship — de-escalation, IV-to-PO, penicillin allergy delabeling, procalcitonin

Parasitic & Tropical Disease

Malaria (P. falciparum — ACT for uncomplicated, IV artesunate for severe), leishmaniasis, babesiosis (atovaquone + azithromycin; exchange transfusion if parasitemia >10%), Chagas (benznidazole), strongyloides hyperinfection

Infection Prevention & Vaccines

ACIP 2024 adult schedule (Shingrix ≥50, RSV ≥60 shared decision, PCV20 or PCV15+PPSV23 ≥65, COVID annual, flu annual, Tdap, HPV catch-up, meningococcal ACWY and B), infection control bundles (CLABSI, VAP, CAUTI), HAI reporting, biothreats (anthrax, plague, VHF Ebola/Marburg)

Sepsis, Bacteremia & Endovascular Infection

Surviving Sepsis Campaign 2021 1-hour bundle, S. aureus bacteremia (TEE when suspicion of endocarditis, 14-day short course for uncomplicated MSSA catheter-related vs 4-6 weeks for complicated), empiric endocarditis vancomycin + ceftriaxone, value of ID consultation in SAB

How to Pass the ABIM Infectious Disease Exam

What You Need to Know

Passing score: Criterion-referenced scaled score (pass/fail)
Exam length: 240 questions
Time limit: ~10-hour exam day (four ~2-hour modules)
Exam fee: ~$2,990 application + exam fee

Keys to Passing

Complete 500+ practice questions
Score 80%+ consistently before scheduling
Focus on highest-weighted sections
Use our AI tutor for tough concepts

ABIM Infectious Disease Study Tips from Top Performers

1Memorize CAP treatment cold per ATS/IDSA 2019: outpatient healthy adult — amoxicillin + macrolide (azithromycin) or doxycycline; outpatient with comorbidities — β-lactam + macrolide or respiratory fluoroquinolone (levofloxacin, moxifloxacin); inpatient non-severe — β-lactam + macrolide or fluoroquinolone; inpatient severe — β-lactam + macrolide or fluoroquinolone, add MRSA coverage (vancomycin or linezolid) and anti-pseudomonal coverage (pip-tazo, cefepime, ceftazidime, meropenem) only when prior isolation, hospitalization + IV antibiotics in last 90 days, or locally validated risk factors

2Know the IDSA C. difficile 2021 update: fidaxomicin is preferred first-line for initial episode (non-severe or severe), vancomycin PO is an acceptable alternative. For recurrent CDI use fidaxomicin or vancomycin taper; consider bezlotoxumab adjunct (single IV infusion) to reduce recurrence or fecal microbiota transplant for multiply recurrent CDI. Metronidazole is no longer first-line for initial CDI

3Master HIV initial ART: first-line regimens are BIC/TAF/FTC (Biktarvy) or DTG/ABC/3TC (Triumeq — requires HLA-B*5701 negative before abacavir) or DTG + TAF/FTC or DTG + 3TC (Dovato). Understand long-acting cabotegravir + rilpivirine (Cabenuva) monthly or q2mo IM after oral lead-in. PrEP — TDF/FTC (Truvada), TAF/FTC (Descovy) for MSM and trans women, or cabotegravir-LA (Apretude) q2mo. PEP — tenofovir-emtricitabine + integrase inhibitor (dolutegravir or raltegravir) ×28 days within 72 hours of exposure

4Lock in OI prophylaxis thresholds in HIV: PJP prophylaxis (TMP-SMX DS daily) when CD4 <200 or oropharyngeal candidiasis; Toxoplasma prophylaxis (TMP-SMX DS daily) when CD4 <100 and Toxo IgG positive; MAC prophylaxis (azithromycin 1200 mg weekly) when CD4 <50 — though current guidelines only recommend if not on effective ART. For PJP pneumonia treatment, add adjunctive corticosteroids when PaO2 <70 mmHg on room air or A-a gradient >35

5Know CDC 2021 STI regimens: gonorrhea — ceftriaxone 500 mg IM × 1 (1 g if ≥150 kg), add doxycycline 100 mg BID × 7 days if chlamydia not excluded; chlamydia — doxycycline 100 mg BID × 7 days (first-line, replaces azithromycin single-dose for most indications); syphilis — benzathine penicillin G 2.4 MU IM × 1 for primary/secondary/early latent; 2.4 MU IM weekly × 3 for late latent, unknown duration, or tertiary (non-neuro); IV penicillin G 18-24 MU/day × 10-14 days for neurosyphilis

Frequently Asked Questions

Who can take the ABIM Infectious Disease exam?

Candidates must hold active ABIM Internal Medicine certification and have satisfactorily completed an ACGME-accredited 2-year Infectious Disease fellowship. The fellowship program director must attest to clinical competence. A valid, unrestricted US medical license and ABIM professional standing are also required.

How is the ABIM Infectious Disease exam structured?

The Infectious Disease exam contains approximately 240 single-best-answer multiple-choice questions administered across four ~2-hour modules on a single ~10-hour test day at Pearson VUE centers. Questions are case-based and emphasize application of current IDSA, CDC, and HHS guidelines (ATS/IDSA CAP 2019, IDSA C. difficile 2021, CDC STI 2021, HHS HIV Clinical Guidelines, IDSA candidiasis and cryptococcosis) rather than rote recall.

What is the passing score for the ABIM Infectious Disease exam?

ABIM uses a criterion-referenced scaled passing score established through standard-setting methodology. The score is reported as pass/fail and the cut point is not publicly disclosed as a percentage. Historical first-time pass rates are approximately 85-90% for candidates who complete an ACGME-accredited Infectious Disease fellowship.

How much does the ABIM Infectious Disease exam cost?

The application fee plus exam fee is approximately $2,990 for initial certification. Costs are subject to change — always confirm on the ABIM website. Total preparation cost including IDSA board review, MKSAP ID, Mandell/Douglas/Bennett Principles and Practice of Infectious Diseases, and a dedicated question bank typically ranges from $3,500 to $5,500.

What topics are emphasized on the ABIM Infectious Disease exam?

The blueprint emphasizes Bacterial Infections and Antimicrobial Therapy (~22%), HIV and Opportunistic Infections (~16%), Mycobacterial Disease (~10%), Viral Infections (~10%), Fungal Infections (~8%), Transplant and Immunocompromised Host (~8%), STIs (~7%), Antimicrobial Stewardship and Resistance (~7%), Parasitic and Tropical Disease (~5%), and Infection Prevention and Vaccines (~5%). High-yield content includes IDSA/ATS CAP 2019, modified Duke criteria, IDSA C. diff 2021 (fidaxomicin first-line), HIV initial ART and Cabenuva long-acting regimens, TB-BPaL, candidemia (echinocandin), and CDC 2021 STI therapy.

How do I maintain ABIM Infectious Disease certification?

ABIM diplomates maintain ID certification through the Longitudinal Knowledge Assessment (LKA) — an open-book, quarterly question set delivered over a 5-year cycle — or through the traditional 10-year recertification exam. Diplomates must also meet MOC activity requirements, hold an active unrestricted medical license, and maintain ABIM professional standing.

How long should I study for the ABIM Infectious Disease exam?

Most candidates study 250-400 hours over 6-12 months in parallel with their 2-year ID fellowship. Preparation typically combines IDSA board review, MKSAP ID, Mandell/Douglas/Bennett, IDSA practice guidelines, and a dedicated question bank. Clinical volume on the inpatient consult service, HIV clinic, and transplant ID service is the strongest predictor of exam success.

Is the ABIM ID exam the same as the ABIM Transplant Hepatology exam?

No. ABIM Infectious Disease is a distinct subspecialty covering the full breadth of bacterial, viral, fungal, mycobacterial, and parasitic infections across outpatient and inpatient settings. Transplant Hepatology is a hepatology subspecialty. Many ID physicians do develop expertise in transplant ID through fellowship tracks or specialty clinics, but the certification pathway is separate.