The Series 66 (Uniform Combined State Law) exam has 100 scored questions (plus 10 unscored), a 73-of-100 passing score, and a 150-minute limit. The fee is $177. It combines the Series 63 and Series 65 into one exam — but it requires a valid Series 7 as a co-requisite before you can register. Nearly half the exam is law and ethics.
The Series 66 exam — officially the Uniform Combined State Law Examination — is a NASAA exam administered by FINRA. It's the efficient path for people who need both qualifications at once: passing the Series 66 qualifies you as if you had passed both the Series 63 (state law for securities agents) and the Series 65 (investment adviser law). In one 100-question sitting, it covers what would otherwise be two exams.
There's one defining condition: the Series 66 requires the Series 7 as a co-requisite. You cannot register as an investment adviser representative on the Series 66 alone — you must also hold a valid Series 7. You can take either exam first, but you need both. That's why the Series 66 is the standard choice for someone already going through the Series 7 at a broker-dealer and moving into a dual agent-plus-adviser role, while the standalone Series 65 suits those who only need the adviser qualification and aren't taking the Series 7.
| Scored questions | 100 (plus 10 unscored pretest) |
| Time limit | 150 minutes (2 hours 30 minutes) |
| Format | Multiple choice, four options (A–D) |
| Passing score | 73 of 100 correct (73%) |
| Fee | $177 (non-refundable) |
| Co-requisite | Valid Series 7 (take either first) |
| Eligibility | No separate sponsor needed to sit the exam |
| Delivery | Prometric center (online only for accommodations) |
The Series 66 is shorter than the Series 65 (100 scored questions versus 130) precisely because it assumes you've already learned securities products through the SIE and Series 7. It doesn't re-test that material in depth — it concentrates on the state and federal law that the product exams don't cover.
NASAA weights the Series 66 across four areas, and the balance is strikingly different from the Series 65 — far more law, far less economics and product detail:
| Content area | Weight | Questions |
|---|---|---|
| I. Economic Factors & Business Information | 8% | 8 |
| II. Investment Vehicle Characteristics | 17% | 17 |
| III. Client Investment Recommendations & Strategies | 30% | 30 |
| IV. Laws, Regulations & Guidelines (incl. Prohibition on Unethical Business Practices) | 45% | 45 |
The headline is Section IV: nearly half the exam is law, regulation, and ethics. That reflects the exam's purpose — it exists to test the state and adviser law layered on top of the product knowledge from the Series 7. Compared with the Series 65 (where law is 30%), the 66 shifts weight decisively toward regulation and away from economics (8% vs 15%) and products (17% vs 25%). If you're preparing, that means your center of gravity should be the regulatory and ethics content: adviser and agent registration, fiduciary obligations, prohibited practices, and communication with clients.
The Series 66 is considered moderately difficult, and its difficulty profile is distinctive. Because it assumes the product knowledge you built for the Series 7, the challenge isn't bonds or options — it's the density of the legal and ethical material and the fine distinctions within it. Nearly half the questions turn on regulatory definitions and prohibited-practice scenarios, where two answer choices often look almost identical. NASAA doesn't publish an official pass rate, so be skeptical of specific figures elsewhere. The real structural difficulty is that a 45% law section leaves no room to be shaky on regulation.
Plan on roughly 40–60 hours, and take advantage of timing: most candidates sit the Series 66 close to the Series 7, while the product material is still fresh, which keeps the shorter economics and investment sections manageable. Direct the bulk of your effort at the law and ethics content — it's the largest section and the one most prone to blurring together under exam pressure.
The Series 66 failure pattern lives in Section IV. Candidates coast on the product-adjacent questions they already know from the Series 7, then lose points on regulatory and ethics items where the distinctions are precise and the answer choices are deliberately close. Reading the law once builds recognition; the exam demands recall of exact rules, weeks later, under time pressure. That gap is a solved problem in cognitive science. The techniques that close it are retrieval practice (quizzing yourself on the rule before you feel ready), spaced repetition (revisiting each legal distinction right as it starts to fade), and immediately re-teaching the scenarios you miss — especially the confident misses.
Trelos is built entirely around those techniques. Instead of a static outline of adviser and agent law, it teaches each rule, drills it with scenario questions in the exam's style, and schedules your reviews so the heavy regulatory section stays sharp right through test day. It's a complete prep engine designed to take you to Series 66 exam-ready on your phone, and you can feel the difference on the first session.
Start the Series 66 on Trelos — freeNo credit card. Feel the retention engine work in your first session.You'll get a pass/fail result immediately. Passing the Series 66 clears the state-law requirement for dual registration — but remember it does nothing on its own. Combined with a valid Series 7, it lets your firm register you with a state as both a securities agent and an investment adviser representative. In adopting states you'll then owe annual IAR continuing education, and NASAA's Exam Validity Extension Program can keep your exam credit valid for up to five years through CE if you step away from the industry. If you're still mapping the finance track, the full sequence runs SIE → Series 7 → Series 66 (or Series 63 + Series 65) for the dual agent-and-adviser path.