The MRCPCH theory component consists of three separate papers that test different things in different ways. Understanding the distinctions is essential for planning your revision — preparing for FOP the same way you prepare for TAS is a common and costly mistake.
FOP — Foundations of Practice
The FOP tests core clinical paediatric knowledge. Questions present clinical scenarios — a child with specific symptoms, investigation results, and history — and ask you to identify the most likely diagnosis, the most appropriate investigation, or the correct management. The content maps to what you encounter in day-to-day paediatric practice during ST1 to ST3.
Format: 95 best-of-five SBA questions in two and a half hours. The questions are clinically grounded and test pattern recognition, diagnostic reasoning, and evidence-based management.
The FOP rewards clinical experience supplemented by guideline reading. If you are working in paediatrics and revising NICE paediatric guidelines alongside a question bank, the FOP is the most straightforward of the three papers.
TAS — Theory and Science
The TAS tests the sciences underpinning child health — not clinical management but the biological mechanisms behind it. The content covers pharmacology (drug mechanisms, pharmacokinetics, paediatric dosing principles), genetics and genomics (inheritance patterns, chromosomal disorders, genetic testing), physiology, pathology, immunology, microbiology, biochemistry, statistics and evidence-based medicine, and ethics.
Format: 95 best-of-five SBA questions in two and a half hours. Questions may use a clinical stem, but the tested construct is the underlying science rather than the clinical decision.
The TAS is where candidates with strong clinical skills but weaker science foundations struggle. Pharmacology accounts for roughly 14 per cent of questions alone. If you have not revised drug mechanisms, receptor pharmacology, and pharmacokinetics since medical school, dedicated TAS preparation is essential.
AKP — Applied Knowledge in Practice
The AKP tests advanced clinical application and complex decision-making. It is pitched at a higher level than the FOP — questions present multi-layered scenarios requiring integration of multiple data points (investigation panels, growth charts, drug charts, fluid balance) and expect you to synthesise rather than simply recognise patterns.
Format: approximately 79 questions in two and a half hours, using two formats. Standard best-of-five SBAs and N-of-many questions where you select two or three correct answers from eight to ten options. The N-of-many format uses all-or-nothing scoring — you must identify every correct answer to get the mark.
The N-of-many format is genuinely different from standard SBA. Elimination strategies work differently when you must find multiple correct answers rather than one. Partial knowledge that would earn you a mark on an SBA (by eliminating wrong options) may earn you nothing on a N-of-many question if you miss one correct answer.
Practising the N-of-many format before exam day is essential. iatroX is currently the only MRCPCH question bank that supports this format.
Which order to sit them
There is no mandatory sequence, but most trainees sit FOP and TAS first (during ST1 to ST3) and AKP later (from ST4 onwards). FOP and TAS can be attempted at the same diet — they are sat on different days within the same window.
Some trainees sit all three papers across two diets: FOP and TAS in one diet, AKP six months later. This approach requires five to six months of total preparation time but accelerates the exam timeline.
Preparation approach
FOP and TAS require different revision strategies because the content domains are almost entirely different. FOP revision should focus on clinical paediatrics — NICE guidelines, RCPCH standards, and clinical pattern recognition. TAS revision should focus on basic sciences — pharmacology textbooks, genetics resources, and statistics primers.
AKP revision should focus on complex clinical reasoning and the N-of-many technique. Start AKP preparation only after you are comfortable with FOP-level clinical knowledge — AKP builds on it.
iatroX offers dedicated question banks for all three papers, each with over 1,500 questions. The FOP bank maps to clinical paediatric guidelines. The TAS bank maps to the sciences curriculum. The AKP bank includes both SBA and N-of-many formats. The adaptive algorithm tracks performance separately across each paper. All three are included at £29 per month or £99 per year.