PrepToPay’s payroll reference library. Clear, current-year explanations of the concepts that payroll professionals and FPC/CPP exam candidates need in practice — written by working payroll pros, cross-checked against IRS, SSA, and DOL source material, and refreshed as rules change.
Every article on this page cites primary sources (IRS publications, SSA bulletins, DOL fact sheets), and every dollar figure reflects the current 2026 plan year. When regulations change mid-year, articles are updated with a dated revision note so you always know what you’re reading against.
Start here
- 2026 Payroll Figures Quick Reference — every limit, rate, and threshold for 2026 on a single page. Social Security wage base ($184,500), Medicare additional tax, 401(k) elective deferral and catch-up limits, HSA/FSA caps, standard mileage, FLSA minimum wage, supplemental withholding rate. Bookmark this one — it’s the page you’ll come back to when the plan year rolls over.
Deep dives
- W-2 Box 12 Codes Explained — what each Box 12 code means and exactly how it flows to Boxes 1, 3, and 5. Covers the codes you see most (D, DD, W, AA, BB, EE) plus the less common ones that show up on multi-state and executive comp W-2s. Includes a reconciliation example that walks from gross wages through pre-tax deferrals to each wage box.
- Additional Medicare Tax (0.9%) — the employer withholding rule that trips up even experienced processors. Who triggers it (wages over $200,000, regardless of filing status), when it kicks in per-pay-period, why there is no employer match, and how it interacts with supplemental wage withholding. Includes edge cases for married-filing-separately households and multi-employer situations.
- SECURE 2.0 Enhanced Catch-Up (Ages 60-63) — the super catch-up window that lets eligible employees defer up to $11,250 extra on top of the regular limit in 2026. Eligibility rules, employer election requirements, interaction with Roth mandatory treatment for high earners, and how to configure the payroll system to apply the right cap.
- FLSA White-Collar Exemption Tests — the salary, salary-basis, and duties tests that determine whether an employee is exempt from overtime under the executive, administrative, professional, outside sales, and computer employee exemptions. Covers the 2024 threshold challenge, current enforcement posture, and the duties-test traps (primary-duty test, discretion and independent judgment).
- OBBBA Dependent Care FSA Increase — the 2026 jump from $5,000 to $7,500 in the dependent care FSA cap under the One Big Beautiful Bill Act. First permanent DCAP increase since 1986. Includes the lower-earning-spouse rule, Box 10 reporting mechanics, FICA treatment, and why there is no carryover or grace period.
How to use this library
These articles are written for three audiences: payroll practitioners doing real processing, FPC/CPP candidates studying for certification, and accounting or HR professionals who need to understand the payroll side of their work. Articles are organized around the concept, not around the exam — so they work whether your goal is a correct W-2 this quarter or a passing exam score in six months.
For full exam preparation including 1,160+ practice questions, timed mocks, and flashcards aligned to the PayrollOrg KSA framework, see the PrepToPay exam prep app.
Practice with PrepToPay
Reading about concepts is step one. The PrepToPay app is where the concepts get exercised — with practice questions written to the same FPC and CPP content outlines PayrollOrg publishes. Every question includes a full explanation of why the correct answer is correct and why the distractors are wrong. Start your 14-day free trial on FPC or CPP. A valid payment method is required at signup; you will not be charged during the trial. Reference is $9.99/month with no trial.
PrepToPay is an independent exam preparation service not affiliated with, endorsed by, or sponsored by PayrollOrg (American Payroll Association). FPC® and CPP® are registered trademarks of PayrollOrg. Use of these marks is for descriptive purposes only. Study questions are written for exam preparation purposes based on publicly available KSA frameworks and do not guarantee exam success or reflect official exam content.