In FL, does a Change Order to a contract extend the deadline for a Bond Claim on a Public Work Job

Generally, a change order can reset the last furnishing date for a project if it's substantial and materially changes (and adds onto) the contract. However, extremely minor work or simple punch list or corrective work typically won't work to reset the last furnishing date. Note also that if it isn't a change order, but it's an entirely new and separate contract, that might begin an entiely separate and new timeline for bond claim rights for that specific work.

For further discussion, the resources below should be useful. Also, while some may address mechanics lien rights and deadlines specifically, note that the concept of last furnishing is generally the same for both mechanics lien rights and payment bond claim rights.

• I Returned to a Job – Does that Change My Deadlines?
• What’s the ‘Date Labor or Materials Last Delivered’ and How Can I Prove It? 

Thanks Matt,

What if the CO is for $29K of materials only on a $2M job? How about if the CO is dated 91 days after the last day of work, (11/11/20 is last day of work, and 2/10/21 is CO date)?

$29k of materials sounds like a pretty significant chunk of work, but there isn't a mathematical benchmark that must be met. As discussed in the articles shared above, as long as the work isn't trivial, then change orders will generally reset the last furnishing date since they represent additional work on the project. 

Regarding a previous last furnishing date, which is followed by additional work via change order - the term and concept of "last furnishing date" refers to the last day when labor or materials are provided to a given project as a whole. So, when additional work is done (beyond minor stuff like punch list, corrective, or warranty work), the previous "last furnishing date" will generally become irrelevant since it no longer represents the claimant's last work on the project. Instead, deadlines are based on the final date that the claimant furnishes labor or materials to that project. 

Here's an additional article that might be helpful: Confusing Dates: What’s the Difference Between Date of Last Furnishing and Date of Substantial Completion?