AdvisorCensus / Financial advisors / Illinois / Chicago / Mainstreet Advisors
Mainstreet Advisors
Filed as MAINSTREET ADVISORS · Legal name Mainstreet Investment Advisors LLC
Mainstreet Advisors is an SEC-registered investment advisory firm in Chicago, IL, registered since 2008, reporting over $5 billion in regulatory assets under management in its Form ADV filing dated March 27, 2026.
Quick answers
From the filingHow is Mainstreet Advisors compensated?
On its Form ADV (Item 5.E, October 2026), Mainstreet Advisors reports these compensation arrangements: a percentage of assets under its management; fixed fees (other than subscription fees).
Where is Mainstreet Advisors located?
Mainstreet Advisors' principal office is in Chicago, IL, according to its Form ADV; the April 2026 filing also lists 1 other office (Schedule D, Section 1.F).
Is Mainstreet Advisors registered with the SEC or a state?
Mainstreet Advisors is an SEC-registered investment advisory firm, registered since 2008. Status as filed: Approved. CRD 146615.
How much does Mainstreet Advisors manage?
Mainstreet Advisors reports $5,855,906,939 in regulatory assets under management in its Form ADV filing dated March 27, 2026 (16% discretionary).
How have Mainstreet Advisors' assets and staff changed since 2021?
In the Form ADV data for Mainstreet Advisors: Regulatory assets under management: $7,776,395,933 in the October 2021 data and $5,855,906,939 in the October 2026 data, down 25%. Total employees: 33 in October 2021 and 26 in October 2026. Assets under management move with markets as well as with clients coming and going.
What types of clients does Mainstreet Advisors serve?
By number of clients on Form ADV Item 5.D: banking or thrift institutions (56); high net worth individuals (2).
Does Mainstreet Advisors report any disciplinary disclosures?
Reports no disclosure items on Form ADV Item 11. The detail of any item is on the firm's SEC record: https://adviserinfo.sec.gov/firm/summary/146615
What changed in Mainstreet Advisors' recent Form ADV filings?
In the February 2026 filing data: Registered or notice-filed in NC.
From the Form ADV filing
Every figure below is as the firm filed it with regulators, as of October 2026.
How the firm is compensated
Item 5.E- A percentage of assets under your management
- Fixed fees (other than subscription fees)
Item 5.E lists how the firm is compensated for its advice; Items 5.B, 6.A, and 7.A show whether its people or related companies can also earn commissions. Percentage of assets, fixed, hourly, subscription, and performance-based fees come from clients (a performance-based fee depends on investment results); commissions come with a sale or a trade, often from the company behind the product. How fees, commissions, and other arrangements differ
Fees and minimums
Form ADV Part 2AThe brochure lists different fees for different services or strategies. See the firm's brochure (dated March 26, 2026) for its fees and any account minimum, on the SEC's IAPD site.
Regulatory assets under management
Item 5.F$5,855,906,939 as of October 2026, filing dated March 27, 2026.
A measure of scale, not skill or returns. Discretionary means the firm decides trades; non-discretionary means clients approve each one. What assets under management means
Who the firm serves
Item 5.DA firm with no individual clients is an institutional manager even if it manages billions; the mix tells you whom the practice is built around.
Advisory services
Item 5.G- Portfolio management for individuals and/or small businesses
- Portfolio management for businesses (other than small businesses) or institutional clients
- Publication of periodicals or newsletters
Registration and firm details
Items 1, 2, 5- Legal name
- Mainstreet Investment Advisors LLC
- Registration
- SEC-registered investment adviser. Status as filed: Approved.
- Registered since
- 2008 (18 years)
- Employees
- Total: 26. Performing investment advisory functions: 6.
- Wrap fee program participation
- No.
- Other offices (Schedule D, Section 1.F)
-
1 other office, as of the April 2026 filing
- States registered or notice-filed
-
10 states or jurisdictions
SEC-registered investment advisers are examined by the SEC. SEC, state, and exempt registration
Disclosures
Item 11None Reports no disclosure items on Form ADV Item 11. View on IAPD.
Item 11 asks about criminal, regulatory, and civil events involving the firm and its advisory personnel. The detail of each yes answer is on the IAPD record. Reading a firm's disclosures
Assets and staff over time
Items 5.A, 5.F| Data period | Assets under management | Employees | Filing dated |
|---|---|---|---|
| October 2026 | $5,855,906,939 | 26 | March 27, 2026 |
| October 2025 | $5,409,800,392 | 22 | July 24, 2025 |
| October 2024 | $5,119,845,804 | 18 | September 26, 2024 |
| October 2023 | $11,202,650,906 | 29 | August 22, 2023 |
| October 2022 | $9,932,088,506 | 32 | March 30, 2022 |
| October 2021 | $7,776,395,933 | 33 | September 10, 2021 |
Regulatory assets under management: $7,776,395,933 in the October 2021 data and $5,855,906,939 in the October 2026 data, down 25%.
Total employees: 33 in October 2021 and 26 in October 2026.
As filed in each year's data for the same month. Assets under management move with markets as well as with clients coming and going; they measure scale, not skill or returns. Most firms update these figures once a year.
Changes in the filing
Last 12 months- February 2026
- Registered or notice-filed in NC.
- January 2026
- Added an office in St Pere, WI.
- No longer registered or notice-filed in AR, AZ, CA, FL, IN, MI, NJ, NY, OH, PA.
Compared month to month from the SEC's monthly adviser data and the state compilation feed. Owners and control persons are summarized, never named.
Websites listed on Form ADV
Item 1.ISource: Form ADV, as of October 2026. Values appear as filed; a value the firm did not report is shown as "Not reported."
Cite this page
AdvisorCensus. Mainstreet Advisors (CRD 146615): Form ADV filing data as of October 2026. https://advisorcensus.com/firm/mainstreet-advisors-chicago-il-146615