The only time you need sign Lien Releases is when you are dealing with sub contractors who work on your job site and when you are dealing with material suppliers who deliver materials to your job site, but your Prime contractor (the contractor you signed your contract with) is not required to give you a signed Lien Release, but many will give you one just to appease you, or because a high percent of contractors don't understand the contracting laws.
The purpose for a Lien Release is so when you (the property owner) has construction work performed you want to make sure all the sub contractors and materials suppliers are paid.
Since you are dealing with only the Prime Contractor (the contractor you hired) the Prime Contractor does not have to sign a Lien Release because you already know you hired the Prime Contractor and you are aware of how much you owe him.
Every sub contractor has to give you a Lien Release because you need to make sure the sub contractors are paid before you pay the final amount to your Prime Contractor.
This is why the Lien Release is for sub contractors and how it works. When you hire the sub contractor many workers show up to work on the job and you don't know Adam from Eve regarding whether or not your Prime Contractor is using sub contractors because your Prime Contractor can lie to you and tell you every worker is one of his employees. Then, after you pay the Prime Contractor all his money you could get bills for thousands of dollars from sub contractors.
TO PREVENT THIS LEGAL PROBLEM WITH SUB CONTRACTORS the sub contractors are required by law to give you what is called a Preliminary Notice within 21 days from the time they start work in most states. This Preliminary Notice is to notify you that they are sub contractors, they are working on your job and the notice tells you that if your Prime Contractor does not pay them then they will come to you for the money and sue you if you don't pay them. So, to make sure you are free from the sub contractors you need them to give you a Lien Release that stated that they have been paid
There are two types of Lien Releases you need to get from sub contractors. The first Lien Releases are for Progress Payments for every time the sub contractor is paid as the job progresses and the second type Lien Release is a Final Payment Lien Release (can't remember the exact name) for when the job is 100% finished.
As the job progresses, the property owner usually writes checks and makes payments directly to the sub contractors.
If a sub contractor fails to give the property owner a Preliminary Notice and nobody pays the sub contractor then the sub contractor is poop-out-of-luck and can sue you and file a Mechanics Lien against your property, but the Mechanics Lien will expire within something like 90 to 120 days and if the sub contractor takes you to court he will lose the case.
I've been a contractor for 50+ years and the following is a clause in my contracts:
"LIEN RELEASE - XYZ CONTRACTOR will never file a Mechanic's Lien on a property unless a payment is not made when due. The Conditional Waiver And Release upon Final Payment is a form that protects you (the Buyer). This form states that after making a payment, when due to XYZ CONTRACTOR, XYZ CONTRACTOR is giving up the right to file a Mechanic's Lien. Since XYZ CONTRACTOR is your prime contractor, XYZ CONTRACTOR is not using sub contractors, and all materials and supplies are delivered directly from XYZ CONTRACTOR'S own warehouse,
XYZ CONTRACTOR, nor XYZ CONTRACTOR employees, nor any of XYZ CONTRACTOR'S suppliers are required to provide you with a lien release. Even so, there is no harm in providing the Lien Release even before XYZ CONTRACTOR receives any payment."
The same Lien Release requirements apply to material suppliers who deliver materials to your job site. Suppose, you hire a Prime Contractor and a lumber company delivers a truckload of lumber. Since you don't know whether the lumber came from your Prime Contractor's warehouse, or whether it came from a lumber company then the lumber company is supposed to give the property owner a Preliminary Notice so the property owner is made aware that if the Prime Contractor does not pay for the lumber then the property owner must make sure the lumber is paid for by the Prime Contractor, or paid for by the property owner, or the property owner will be sued. So, the property owner is required to give all materials suppliers a signed Lien Release and, of course, it is better to get those lien releases from the materials suppliers and sub contractors before paying the Prime Contractor.
Most property owners and even most contractors don't understand the Lien Release laws and Prime Contractors try to make their life easy by giving every customer a Lien Release, but since many contractors don't understand the laws the customers get ripped off and end up paying for their work several times before lawsuits are settled.
It is good to know that you can tell sub contractors and materials suppliers to pound sand when they don't provide you with a Preliminary Notice. Otherwise, how would you know whether or not sub contractors are working on your job.