Advisor Selection

Regulation Best Interest vs. Fiduciary Duty: What Physicians Should Know

By the Attend Wealth team · Updated August 2026 · 6 min read

Physicians are told to hire a fiduciary. Fewer are told what the alternative standard requires, or how to tell which one governs the person across the table.

Quick answer

Fiduciary duty under the Investment Advisers Act applies to registered investment advisers across the whole relationship and includes duties of care and loyalty. Regulation Best Interest, effective June 2020, applies to broker-dealers at the moment of a recommendation and requires acting in the retail customer's best interest. Reg BI replaced the older suitability standard and is generally understood to be less demanding than the Advisers Act duty.

What fiduciary duty requires

The Advisers Act imposes a duty of care and a duty of loyalty. Care means providing advice in the client's best interest based on their objectives, seeking best execution, and monitoring over the course of the relationship. Loyalty means not subordinating the client's interest to the adviser's, and eliminating or fully disclosing conflicts so the client can give informed consent.

Critically, it applies to the relationship, not to individual transactions. An adviser cannot satisfy it at the moment of a recommendation and disregard it afterward.

What Reg BI requires

Reg BI obligates a broker-dealer and its representatives to act in the retail customer's best interest when making a recommendation, without placing their own interests ahead of the customer's. It comprises four obligations: disclosure, care, conflict of interest, and compliance.

It applies at the point of recommendation rather than continuously, and it does not impose an ongoing monitoring duty absent an agreement to provide one. That is the practical gap between the two standards.

The suitability claim you should stop repeating

A great deal of published comparison content still says brokers are held only to a suitability standard, meaning a recommendation need only be appropriate rather than best. That was accurate before June 2020 and has been outdated since.

It matters because physicians using that framing may over-weight the distinction, or may dismiss a competent dually registered advisor on inaccurate grounds. The gap between the standards is real; it is narrower than the older framing suggests.

How to tell which one governs your relationship

Many advisors are dually registered, meaning they can act as an investment adviser representative in some contexts and a broker-dealer representative in others. This is legal and common, and the standard that applies depends on the capacity in which they are acting.

Ask which capacity applies to your relationship, ask whether it changes for any part of the engagement, and get it in writing. Check both adviserinfo.sec.gov and FINRA BrokerCheck to see the registrations.

  • Is our relationship an advisory relationship or a brokerage relationship?
  • Does the capacity change for any part of the engagement?
  • Are you dually registered? Which registration applies to this account?
  • Will you confirm the applicable standard in writing?

Where compensation fits in

Neither standard is determined by compensation model. A fee-based registered investment adviser is a fiduciary. A commission-compensated broker is under Reg BI. A dually registered person may be either depending on context.

So compensation and legal standard are two separate screens, and a physician should apply both rather than assuming one implies the other.

Related physician planning questions

What is the difference between Reg BI and fiduciary duty?

Fiduciary duty under the Investment Advisers Act applies to registered investment advisers across the entire relationship and includes duties of care and loyalty with ongoing monitoring. Regulation Best Interest applies to broker-dealers at the point of a recommendation and requires acting in the retail customer's best interest, but does not impose continuous monitoring absent agreement.

Are brokers still held to a suitability standard?

No. Regulation Best Interest took effect in June 2020 and replaced the suitability standard for recommendations to retail customers. Published content still describing brokers as suitability-only is out of date.

What does dually registered mean?

An advisor registered both as an investment adviser representative and as a broker-dealer representative. Which legal standard applies depends on the capacity in which they are acting for a given account or recommendation. Ask which capacity governs your relationship and get it in writing.

Does compensation determine which standard applies?

No. The standard follows registration, not compensation. A fee-based registered investment adviser is a fiduciary; a commission-compensated broker is under Reg BI. Screen for both compensation and registration separately.

Related insights

See how this fits into a physician-focused plan.

Attend Wealth helps physicians connect planning, taxes, investing, insurance, and retirement decisions into one strategy. If you want help applying this topic to your own loans, taxes, investments, or retirement plan, schedule a complimentary conversation.

This article is for educational purposes only and is not personalized financial, tax, or legal advice. Attend Wealth is a registered investment adviser and acts as a fiduciary to its advisory clients. Attend Wealth is fee-based: in addition to advisory fees, our advisors are licensed insurance professionals and may receive commissions on insurance policies placed through carriers including Guardian, MassMutual, Ameritas, Principal, The Standard, and Lloyd's. That compensation creates a conflict of interest. We describe it, and how we address it, in our Form ADV Part 2A and Form CRS, available at adviserinfo.sec.gov or on request. Please consult a qualified professional about your specific situation.