Series 66 vs SIE: How the Two Exams Fit Together
The SIE® and the Series 66 aren’t alternatives: they’re different steps on the same path. The SIE is FINRA’s entry-level exam on how the securities industry works; the Series 66 is NASAA’s combined state-law exam that, paired with the Series 7, registers you as both a broker-dealer agent and an investment adviser representative. On the dual-registration path, the SIE isn’t just recommended before the 66: it’s a co-requisite for registering through it. Comparison verified July 2026; retake waits rechecked October 2026.
The two exams, side by side
| Attribute | SIE | Series 66 |
|---|---|---|
| Owner | FINRA | NASAA (FINRA administers) |
| Role | Entry exam: industry fundamentals | State-law exam for dual agent + adviser-rep registration |
| Fee | $100 | $177 |
| Scored questions | 75 (+10 unscored; 85 on screen) | 100 (+10 unscored; 110 on screen) |
| Time | 1 hour 45 minutes | 2 hours 30 minutes |
| Passing score | 70 (scaled) | 73 of 100 scored |
| Sponsorship to sit | Not required: anyone 18+ | Not required: but SIE + Series 7 are co-requisites to register through it |
| Validity of a pass | 4 years | While registered + 2 years after leaving a firm (to 5 via NASAA’s EVEP in participating states) |
| Retake waits | 30/30/180 days through January 18, 2027; 15/15/60 days from January 19, 2027 (Regulatory Notice 26-18) | 30/30/180 days now; 30/30/60 for enrollment windows opened on or after January 4, 2027 (NASAA’s own change, separate from FINRA’s) |
| Pass rate | 74% first-time, FINRA’s only published figure, from the exam’s early years | Not published; prep estimates run roughly 65–70% (estimates only) |
Different regulators, different questions
The clean way to keep them straight is by who’s asking:
- The SIE is FINRA asking whether you understand the industry: products and their risks, trading and settlement, market structure, and the federal regulatory framework. It’s the foundation everything on the brokerage path builds on.
- The Series 66 is the states asking whether you can be trusted with clients under their laws: the Uniform Securities Act (the model law state securities statutes are built on), who must register and who’s exempt, fiduciary duty, and unethical practices, plus a recommendations section that turns product knowledge into advice.
The overlap is real but limited: the 66’s economic-factors and investment-vehicles sections (25% combined) revisit SIE territory, while its dominant law-and-ethics section (45%) is material the SIE barely touches.
How they fit on the path
Becoming a dual-hatted representative, agent and investment adviser representative at the same firm, takes three exams and a firm:
- SIE: take it anytime, 18 or older, no firm needed. Almost always first.
- Series 7: after a member firm sponsors you.
- Series 66: no sponsor needed to sit, but a 66 pass only completes the registrations once the SIE and Series 7 are passed too. Most candidates take it during the same onboarding stretch as the Series 7.
If your career only needs one of the 66’s two halves, the comparison changes: brokerage-only agents take the Series 63 instead (SIE vs Series 63), and advisory-only careers run through the Series 65, which needs no SIE at all (SIE vs Series 65). The 66 is specifically the both-hats exam, more on what that means on what is the Series 66.
Which to take first
The SIE, in almost every case. It’s the cheapest, it’s the foundation the other exams assume, its pass is valid for 4 years, comfortably covering a job search, and it’s the only exam on this path most people can finish before a firm hires them. Showing up with it done shortens onboarding, and the fundamentals it drills into you are the raw material of the 66’s vehicles and recommendations sections.
That first step is also the one you can practice right now, free: take a free SIE practice exam, verified, cited answers, no card, no signup. When you’re mapping the rest of the path, the Series 66 exam guide has the full facts table and outline.
We also keep this comparison written from the SIE’s side at SIE vs Series 66, same facts, opposite vantage point.