401(k)
2023 plan-year 401(k) DOL Form 5500

ONS SAVINGS PLAN

ERISA Form 5500 plan record drawn from DOL EBSA — verify with linked source filings below.

ONS MSO, LLC

This 401(k) plan holds $105M in total assets and serves 688 participants as of 2023. It is sponsored by ONS MSO, LLC in Connecticut. The plan reported positive net income of $51M for the year.

Total Assets (2023)
$105M
Participants
688
State
Industry
Healthcare & Social Assistance

What the Filing Says About ONS SAVINGS PLAN

ONS SAVINGS PLAN is a 401(k) retirement plan sponsored by ONS MSO, LLC, headquartered in Connecticut. As of the 2023 Form 5500 filing, the plan reports $105M in total end-of-year assets and covers 688 participants across the Healthcare & Social Assistance industry. The sponsor's EIN on file with the U.S. Department of Labor is 841758967, and the plan has been effective since 1998-10-01. Its filing status is currently FILING RECEIVED.

Year over year, total assets moved from $55M at the beginning of 2023 to $105M at year-end — a gain of 93.0%. Net assets (after liabilities) closed the year at $105M, with reported net income of $51M driven by investment returns, contributions received, and benefit payments during the period. These figures reflect what the plan administrator certified on Schedule H or Schedule I of the Form 5500 annual return and can be compared against 2 prior plan-year filings from the same sponsor shown below.

Asset totals and participant counts reflect a single plan year snapshot and can change materially with market conditions, plan mergers, or workforce changes. Fields such as "net income" include both realized investment performance and contribution/distribution flows — a single-year figure does not by itself indicate plan health or participant outcomes. This page summarizes public DOL disclosures for research and educational purposes only and is not retirement, tax, legal, or financial advice. Before making decisions about your own retirement benefits or evaluating an employer's plan, verify the underlying filing directly via the DOL EFAST2 system and consult a qualified professional.

Financial Summary (2023)

Total Assets (Beginning of Year)$55M
Total Assets (End of Year)$105M
Net Assets (End of Year)$105M
Net Income$51M
Plan Type401(k)
Employer EIN841758967
Plan Effective Date1998-10-01
Filing StatusFILING RECEIVED

Sponsor Plan History (ONS MSO, LLC)

Year Plans Participants Total Assets
2022 1 443 $55M
2023 1 688 $105M
2024 1 1,230 $133M

Nearby 401(k) Plans in Connecticut

Peer 401(k) plans — same state, same plan type — ranked by total assets.

Frequently Asked Questions

How much money is in the ONS SAVINGS PLAN?
As of the 2023 Form 5500 filing, ONS SAVINGS PLAN holds $105M in total assets with 688 participants. It is sponsored by ONS MSO, LLC.
What type of plan is ONS SAVINGS PLAN?
ONS SAVINGS PLAN is a 401(k) plan. It has been effective since 1998-10-01. The plan is filed with the U.S. Department of Labor under EIN 841758967.
Who sponsors the ONS SAVINGS PLAN?
ONS SAVINGS PLAN is sponsored by ONS MSO, LLC, located in Connecticut. The sponsor's EIN is 841758967 and the plan operates in the Healthcare & Social Assistance industry.
How did ONS SAVINGS PLAN perform in 2023?
ONS SAVINGS PLAN grew by 93.0% during 2023, moving from $55M to $105M in total assets. Net income was $51M.
Where can I find official filings for ONS SAVINGS PLAN?
Official Form 5500 filings for ONS SAVINGS PLAN are available through the U.S. Department of Labor's EFAST2 system. Search by EIN 841758967 or plan name at efast.dol.gov.
How does ONS SAVINGS PLAN compare to other plans?
You can compare ONS SAVINGS PLAN against other 401(k) plans on the plan type page, or view plans in Connecticut on the state page. PlainRetire tracks the 5,000 largest retirement plans in the U.S. by total assets.

Explore PlainRetire

Source: U.S. Department of Labor, Employee Benefits Security Administration (EBSA), Form 5500 public disclosure dataset. Plan year 2023.

Source: DOL EFAST2 filing system (efast.dol.gov) — original filing retrieval by EIN 841758967.

Reference: IRS Publication 560 — Retirement Plans for Small Business, contribution-limit rules.

Reference: IRS Publication 590-B — Distributions from IRAs, RMD rules under SECURE Act 2.0.

Data sourced from official public datasets. See our methodology for details.