# Mainstreet Advisors

> 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.

- CRD: 146615
- Filed as: MAINSTREET ADVISORS
- Legal name: Mainstreet Investment Advisors LLC
- Registration: SEC-registered investment adviser (status as filed: Approved)
- Location: Chicago, IL
- Filing period: October 2026
- Form ADV filing dated: March 27, 2026
- SEC record (IAPD): https://adviserinfo.sec.gov/firm/summary/146615
- AdvisorCensus page: https://advisorcensus.com/firm/mainstreet-advisors-chicago-il-146615

## Quick answers

**How 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). The amounts are in Item 5 of its Form ADV Part 2A brochure.

**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

### Compensation (Item 5.E)
- A percentage of assets under your management
- Fixed fees (other than subscription fees)

### Regulatory assets under management (Item 5.F)
- Total: $5,855,906,939
- Discretionary: $963,175,893
- Non-discretionary: $4,892,731,046

### Clients (Item 5.D)

| Client type | Clients | Assets |
| --- | --- | --- |
| High net worth individuals | 2 | $3,138,178 |
| Banking or thrift institutions | 56 | $5,852,768,761 |

### 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

### Firm details
- Registered since: 2008 (18 years)
- Employees: 26 total, 6 performing advisory functions
- Wrap fee program participation: No
- States registered or notice-filed: CT, IA, IL, LA, NC, NE, NM, TN, TX, WI
- Disclosures (Item 11): Reports no disclosure items on Form ADV Item 11.

### Other offices (Schedule D, Section 1.F), as of the April 2026 filing
- St Pere, WI

### Websites listed on Form ADV (Item 1.I)
- mainstreetadv.com
- LinkedIn @mainstreet-advisors-llc

## Assets and staff over time

| Data period | Regulatory assets under management | Employees | Filing dated |
| --- | --- | --- | --- |
| October 2021 | $7,776,395,933 | 33 | September 10, 2021 |
| October 2022 | $9,932,088,506 | 32 | March 30, 2022 |
| October 2023 | $11,202,650,906 | 29 | August 22, 2023 |
| October 2024 | $5,119,845,804 | 18 | September 26, 2024 |
| October 2025 | $5,409,800,392 | 22 | July 24, 2025 |
| October 2026 | $5,855,906,939 | 26 | March 27, 2026 |

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.

## 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.

## Source

Form ADV as filed, October 2026. Values appear as filed. Cite as: AdvisorCensus. Mainstreet Advisors (CRD 146615): Form ADV filing data as of October 2026.