Cosgrove Custom Pools Inc
This license is C-53 only. A pool project that also includes a patio cover, outdoor kitchen electrical, or work on the house may need other licensed trades.
License record
| Business type | Corporation |
|---|---|
| Licenses held | C-53 Swimming Pool |
| First licensed | July 1, 2015 (11 years) |
| License expires | July 31, 2027 |
| Bond | $25,000 contractor's bond, Merchants Bonding Company (mutual) |
| Workers' comp | Workers' Compensation Insurance, WCF National Insurance Company, through December 10, 2026 |
| Phone on file | (530) 305-2608 |
People on the license
- Mason Lynn Cosgrove: Qualifier (RMO), CEO/President (C-53 Swimming Pool)
Other pool builders in Loomis
- French Pool Excavation · license #1111908
- Golden Valley Development · license #1030793
- Granite Pools · license #654656
- J C Custom Pools Inc · license #1105230
What a pool contractor checks here
The $25,000 contractor's bond is the legal minimum, and it is shared by everyone with a claim against this license. On a $100,000 pool it covers very little, so it is not a substitute for a good contract.
Before you sign: confirm the license is active on that day, that the business name and license number on the contract match this record exactly, and that the salesperson is either on this license or registered with CSLB as a home improvement salesperson. The full checklist.
Your next steps
- Got a bid or a contract? Have a licensed pool contractor review it before you sign.
- What's not in your pool contract: the items most often left out.
- Which pool equipment should I get? Pentair, Hayward or Jandy.
- The before-you-sign checklist: what California requires in the contract.
Source: Contractors State License Board, Statewide Public Database Files (License Master and Personnel), as of November 6, 2026. Status can change at any time: check license #1005123 live at CSLB. Something wrong on this page? Request a correction.