401(k) glossary

·

Fiduciary & roles

3(16) fiduciary (plan administrator)

Short definition

A 3(16) fiduciary is the plan administrator defined in section 3(16) of ERISA, responsible for running the plan day to day. If the plan document names no one else, the employer is the 3(16) administrator.

What a 3(16) fiduciary is

Section 3(16) of ERISA defines the “administrator” of a plan as the person named for that job in the plan document, and the plan sponsor if no one is named. The administrator is responsible for operating the plan according to its terms: signing and filing Form 5500, delivering required notices and disclosures, deciding eligibility and claims, and approving loans and distributions.

Employers can hire a provider to accept this role in writing. The scope varies. Some providers take on the full administrator role, and others accept a specific list of duties and leave the rest with the employer.

Why it matters to employers

Administrative errors are the most common way plans get into trouble: a late filing, a missed notice, an employee enrolled late. A 3(16) provider that has accepted responsibility for a task is accountable for doing it correctly. What it does not remove is your duty to select and monitor that provider prudently, or your responsibility for the data you send. A provider cannot file accurately from an incomplete census.

Example

A service agreement lists the provider’s 3(16) duties as: preparing and signing Form 5500, sending annual notices, approving distributions and loans, and tracking eligibility. Depositing contributions on time is not on the list. A late deposit is still the employer’s responsibility.

Common mistakes

  • Assuming “3(16)” means the same thing with every provider. Read the list.

  • Confusing a 3(16) administrator with a third-party administrator (TPA). Many TPAs do the work without accepting fiduciary responsibility for it.

  • Expecting a 3(16) fiduciary to choose investments. That is a 3(21) or 3(38) role.

  • Not reviewing the provider’s work each year.

Sources

U.S. Code (govinfo.gov): 29 U.S.C. 1002 (ERISA section 3): Definitions (https://www.govinfo.gov/content/pkg/USCODE-2023-title29/html/USCODE-2023-title29-chap18-subchapI-subtitleA-sec1002.htm), retrieved 2026-11-11 U.S. Department of Labor, EBSA: Meeting your fiduciary responsibilities (https://www.dol.gov/agencies/ebsa/about-ebsa/our-activities/resource-center/publications/meeting-your-fiduciary-responsibilities), retrieved 2026-11-11 U.S. Code (govinfo.gov): 29 U.S.C. 1105 (ERISA section 405): Liability for breach of co-fiduciary (https://www.govinfo.gov/content/pkg/USCODE-2023-title29/html/USCODE-2023-title29-chap18-subchapI-subtitleB-part4-sec1105.htm), retrieved 2026-11-11

General information, not legal or tax advice.

© 2026 Basic Capital. All rights reserved.

Basic Capital Group, Inc. and its affiliates and subsidiaries (collectively, "Basic Capital") provide this website and its contents for informational and educational purposes only. The information on this website is general in nature and is not intended to address the circumstances of any particular individual or entity.  Nothing on this website constitutes investment, financial, legal, tax, or accounting advice, nor should it be construed as a recommendation or endorsement of any specific investment product, strategy, or service. Basic Capital does not provide legal, tax, or accounting advice. You should consult with your own qualified financial, legal, and tax advisors before making any investment decisions. Our site uses a third party service to match browser cookies to your contact information. We then use another company to send special offers on our behalf.

Recordkeeping Services

Recordkeeping services are provided through Basic Capital Recordkeeping Services LLC, a wholly owned subsidiary of Basic Capital Group, Inc. Unless expressly agreed to in writing, Basic Capital Recordkeeping Services LLC does not act as a fiduciary under the Employee Retirement Income Security Act of 1974, as amended, with respect to any employee benefit plan.

Investment Advisory Services

Investment advisory services are provided through Basic Capital Advisors LLC, a wholly owned subsidiary of Basic Capital Group, Inc. registered with the State of New York as an investment adviser. Registration does not imply a certain level of skill or training. Investing involves risk, including the potential loss of principal. Past performance is not indicative of future results.
Investments in securities are: Not FDIC Insured • Not Bank Guaranteed • May Lose Value.
Neither Basic Capital Advisors LLC nor its affiliates are a registered broker-dealer or engage in securities brokerage activities. Furthermore, Basic Capital Advisors LLC and its affiliates do not act as a broker-dealer.

Basic Capital, 52 Walker Street, 5th Floor, New York, NY 10013 | 888-460-4901

© 2026 Basic Capital. All rights reserved.

Basic Capital Group, Inc. and its affiliates and subsidiaries (collectively, "Basic Capital") provide this website and its contents for informational and educational purposes only. The information on this website is general in nature and is not intended to address the circumstances of any particular individual or entity.  Nothing on this website constitutes investment, financial, legal, tax, or accounting advice, nor should it be construed as a recommendation or endorsement of any specific investment product, strategy, or service. Basic Capital does not provide legal, tax, or accounting advice. You should consult with your own qualified financial, legal, and tax advisors before making any investment decisions. Our site uses a third party service to match browser cookies to your contact information. We then use another company to send special offers on our behalf.

Recordkeeping Services

Recordkeeping services are provided through Basic Capital Recordkeeping Services LLC, a wholly owned subsidiary of Basic Capital Group, Inc. Unless expressly agreed to in writing, Basic Capital Recordkeeping Services LLC does not act as a fiduciary under the Employee Retirement Income Security Act of 1974, as amended, with respect to any employee benefit plan.

Investment Advisory Services

Investment advisory services are provided through Basic Capital Advisors LLC, a wholly owned subsidiary of Basic Capital Group, Inc. registered with the State of New York as an investment adviser. Registration does not imply a certain level of skill or training. Investing involves risk, including the potential loss of principal. Past performance is not indicative of future results.
Investments in securities are: Not FDIC Insured • Not Bank Guaranteed • May Lose Value.
Neither Basic Capital Advisors LLC nor its affiliates are a registered broker-dealer or engage in securities brokerage activities. Furthermore, Basic Capital Advisors LLC and its affiliates do not act as a broker-dealer.

Basic Capital, 52 Walker Street, 5th Floor, New York, NY 10013 | 888-460-4901

© 2026 Basic Capital. All rights reserved.

Basic Capital Group, Inc. and its affiliates and subsidiaries (collectively, "Basic Capital") provide this website and its contents for informational and educational purposes only. The information on this website is general in nature and is not intended to address the circumstances of any particular individual or entity.  Nothing on this website constitutes investment, financial, legal, tax, or accounting advice, nor should it be construed as a recommendation or endorsement of any specific investment product, strategy, or service. Basic Capital does not provide legal, tax, or accounting advice. You should consult with your own qualified financial, legal, and tax advisors before making any investment decisions. Our site uses a third party service to match browser cookies to your contact information. We then use another company to send special offers on our behalf.

Recordkeeping Services

Recordkeeping services are provided through Basic Capital Recordkeeping Services LLC, a wholly owned subsidiary of Basic Capital Group, Inc. Unless expressly agreed to in writing, Basic Capital Recordkeeping Services LLC does not act as a fiduciary under the Employee Retirement Income Security Act of 1974, as amended, with respect to any employee benefit plan.

Investment Advisory Services

Investment advisory services are provided through Basic Capital Advisors LLC, a wholly owned subsidiary of Basic Capital Group, Inc. registered with the State of New York as an investment adviser. Registration does not imply a certain level of skill or training. Investing involves risk, including the potential loss of principal. Past performance is not indicative of future results.
Investments in securities are: Not FDIC Insured • Not Bank Guaranteed • May Lose Value.
Neither Basic Capital Advisors LLC nor its affiliates are a registered broker-dealer or engage in securities brokerage activities. Furthermore, Basic Capital Advisors LLC and its affiliates do not act as a broker-dealer.

Basic Capital, 52 Walker Street, 5th Floor, New York, NY 10013 | 888-460-4901