Two advisors can recommend two different products on the same day, to the same client, and both recommendations can be legal. Only one of them is required to be in your best interest. Here is the legal line between the suitability standard, Regulation Best Interest, and the fiduciary duty — and how to tell which one applies to your advisor.
A recommendation must be appropriate for the client's profile — not necessarily the best available option.
A recommendation must be in the client's best interest at the time of sale, considering reasonably available alternatives.
The advisor must act in the client's best interest at all times, with conflicts disclosed and mitigated, across the entire relationship.
Suitability has been replaced by Reg BI for new broker-dealer recommendations since 2020 — but understanding it matters because Reg BI only narrowed the gap. It did not close it. The fiduciary standard remains the highest bar.
What each standard actually requires, what its limits are, and where it comes from in regulation.
| Dimension | Suitability | Reg BI | Fiduciary |
|---|---|---|---|
| Applies to | Broker-dealers (pre-2020) | Broker-dealers (2020 onward) | Investment Advisers |
| What the recommendation must be | Suitable for the client's profile | In the client's best interest at time of sale | In the client's best interest, always |
| Conflict-of-interest treatment | Limited disclosure | Must be disclosed | Must be disclosed AND mitigated |
| Ongoing duty to monitor | No | Only at moment of recommendation | Continuous, throughout the relationship |
| Standard of care | Reasonable basis to believe suitable | Care, skill, and diligence at point of recommendation | Skill, prudence, and diligence of a reasonable professional |
| Authority | FINRA Rule 2111 | SEC Reg BI (Release 34-86031) | Investment Advisers Act §206 + SEC interpretive releases |
| Where to verify the advisor | FINRA BrokerCheck | FINRA BrokerCheck | SEC IAPD (adviserinfo.sec.gov) |
The fiduciary standard for Investment Advisers comes from the Investment Advisers Act of 1940 and the Supreme Court's 1963 decision in SEC v. Capital Gains Research Bureau. For the eighty years since, anyone who is paid for advising on securities has owed a fiduciary duty to their client. That part has not changed.
What changed is the standard for brokers — the people who sell securities for a commission rather than charging a client fee for advice. From the 1930s through 2020, brokers were governed by FINRA's suitability rule, which required a recommendation to be appropriate for the client's profile but did not require it to be the best available option. The SEC studied the standard in its 2011 report to Congress under Section 913 of Dodd-Frank and found that retail investors were broadly confused about which standard applied to their advisor — and that commission-driven recommendations often produced worse outcomes for customers.
The Department of Labor tried to apply a fiduciary standard to retirement accounts in 2016, but the Fifth Circuit vacated that rule in 2018. The SEC's answer in 2020 was Regulation Best Interest — a compromise that strengthens suitability without elevating it to a fiduciary duty. Reg BI requires brokers to consider reasonably available alternatives and to recommend something defensibly in the customer's best interest, but it does not require ongoing monitoring, it does not require conflicts to be mitigated rather than just disclosed, and it does not require the recommendation to be the genuinely best option.
That is why three standards exist for what the consumer experiences as one conversation. The fiduciary standard is the oldest and the strongest. Reg BI is the newest and the middle ground. Suitability is the historical floor that Reg BI replaced — and understanding all three is how a consumer figures out which one their advisor actually owes them today.
A 55-year-old saver with a $400,000 balance asks their advisor to recommend a diversified large-cap mutual fund for a long-term retirement allocation. The advisor has access to two options:
Both funds are suitable for the client's profile. The broker can recommend Fund B, earn the load and the ongoing trail, and be in compliance — as long as they document a reasonable basis for the recommendation.
The broker must consider reasonably available alternatives and recommend something in the client's best interest. They are required to disclose the conflict — that they earn more on Fund B — but they can still recommend Fund B if they can defend the choice on factors other than cost (for example, brand, performance history, or active management).
The advisor must recommend the option genuinely best for the client. With identical risk exposure and a ninety-basis-point cost gap, Fund A is the recommendation a fiduciary owes. The advisor cannot recommend Fund B simply because it pays them more — the duty of loyalty is the whole point.
All three outcomes are legal under their respective standards. They are also three different bills for the client over thirty years.
We run a fiduciary directory. We are not arguing that every consumer needs a fiduciary on every transaction. The fiduciary standard is the right answer for ongoing advice. The Reg BI side of the line — brokers, transaction-based relationships — has legitimate uses. Honesty matters here.
The fiduciary standard becomes the right answer the moment the relationship turns into ongoing advice — retirement planning, tax-aware investing, drawdown sequencing, estate coordination. That is what the standard is built for. Below that threshold, Reg BI is genuinely fine.
Any of these in a Form ADV, Form CRS, or written response from your advisor means there is some part of the relationship where the fiduciary standard does not apply. That is not necessarily disqualifying — but it is worth knowing.
Every advisor in the Fiduciary Check directory is a fee-only Investment Adviser. No dual registration, no Reg BI workarounds, no other hat to swap into. The fiduciary standard applies to every recommendation, every time.