A mechanics’ lien is a claim against your property, filed in court by a contractor or subcontractor who says it was not paid for labor or materials that went into the work. In Pennsylvania, the Mechanics’ Lien Law of 1963, as amended through 2014, sets the rules. The claim has to be for more than $500 and has to be filed with the county prothonotary, the clerk of the civil court, within six months after the claimant finished its work. If you live in a one- or two-unit house or a townhouse and have paid the full contract price to your general contractor, a subcontractor generally cannot file a lien against it.
The summary below follows the statute text published by the Pennsylvania General Assembly. Liens involve court procedure and deadlines that turn on the facts of a job. If you receive a notice or find a lien on your property, talk to a lawyer.
Who can file
The law gives lien rights to two groups. A contractor is anyone who works under a contract with the owner, including a builder, a trade contractor hired directly, a supplier who sells to the owner, or an architect or engineer who also supervises the work. A subcontractor is anyone who works under a contract with the contractor, or with a subcontractor that has a direct contract with the contractor. The law excludes anyone further down the chain, anyone whose contract is with a supplier, and an architect or engineer hired by a contractor or subcontractor.
Every lien attaches to the improvement and the owner’s interest in the property, and the debt must be one the owner owes the contractor or the contractor owes a subcontractor. Under the law, the right to a lien exists even if the job is never finished, as long as that was not the claimant’s fault and the building was not destroyed by fire or another casualty.
Protection for owners who paid in full
A 2014 amendment added a protection for homeowners. A subcontractor has no right to a lien on residential property when all of these are true:
- The owner or tenant has paid the full contract price to the contractor.
- The property is, or is meant to be, the owner’s residence, or a tenant’s residence after the owner occupied it.
- The building is a single townhouse or has one or two dwelling units.
The protection applies to subcontractors only. Your own contractor keeps its lien rights for any amount you still owe it.
Deadlines
| Step | Deadline in the statute |
|---|---|
| Subcontractor’s formal written notice to the owner of intent to file | At least 30 days before the claim is filed |
| Claim filed with the prothonotary | Within six months after the claimant completes its work |
| Written notice of the filing served on the owner | Within one month after the claim is filed |
| Affidavit of service filed | Within 20 days after the notice is served |
| Lawsuit to obtain judgment on the claim | Within two years of filing, unless the owner extends the time in writing |
| Verdict or judgment | Within five years of filing, or the claim is lost |
The subcontractor’s 30-day notice has to state who is claiming, who it contracted with, the amount, what labor or materials it furnished, the date it finished, and a description of the property. It can be mailed first class, registered or certified, or delivered in person, and if neither works it can be posted on the property. Treat any such notice as urgent. It tells you a claim may follow, and it gives you time to find out whether your contractor has paid the subcontractor.
For most work on an existing house, which the law calls alteration or repair, the lien takes effect on the date the claim is filed. For new construction or a substantial addition, it takes effect from the date work visibly began on the ground.
Lien waivers
For residential property, a contractor or subcontractor may give up the right to file a claim in a written instrument it signs. A contract between you and the contractor, or a separate document the contractor signs, that says no one will file a claim also binds subcontractors, but only if a subcontractor had actual notice of it before starting work, or the document was filed with the prothonotary within the deadlines the law sets. Those deadlines are before work begins on the ground, within ten days after the main contract is signed, or at least ten days before the subcontractor’s own contract.
A release signed by a claimant does not give up its right to file for labor or materials furnished later, unless the release says so. Ask your lawyer how a waiver should be worded for your job, and see the change orders and payments guide for tying waivers to each payment.
Limiting subcontractor claims to what you still owe
When subcontractors’ claims add up to more than the unpaid balance of your contract, the law lets you ask the court to limit each claim to its share of the balance. This applies when each subcontractor knew the contract price and payment terms before starting work, or when the contract was filed with the prothonotary as the law describes. A subcontractor can also rescind its own contract if your contract with the general contractor reduces its rights or delays your payment more than four months past completion, unless it was told of those terms in advance or they were filed.
If a lien is filed
The statute gives the owner several tools:
- After a subcontractor finishes, you or the contractor can file a rule in court requiring it to file any claim within 30 days or lose the right.
- You can file preliminary objections to a claim that does not conform to the law or covers exempt property.
- You can have the lien discharged from the property by depositing the amount of the claim with the court while the dispute is decided.
- If you sell the house in good faith for value before a claim for alterations or repairs is filed, the statute says the lien is wholly lost.
A lien can also come up as a threat during a payment dispute. In an August 14, 2026 announcement of a lawsuit against a paving contractor, the Attorney General’s office said a Dauphin County homeowner paid $32,000 on a $16,000 contract because he feared a lien on his property. The office’s complaint alleges that terms were added to his contract without his knowledge. A contractor’s claim still has to meet the statute’s requirements, and a lawyer can tell you whether one does.
How to check for a lien
Mechanics’ lien claims are filed with the prothonotary of the county where the property sits. In Montgomery County, the Prothonotary’s office says its online Civil Viewer can search for civil suits and liens by the name of a person or business. Viewing docket entries or filings online requires payment by card. Copies made at the office cost 25 cents a page, and docket printouts cost $1.75 a page, according to the office.