If we sign an unconditional waiver and release on progress payment for our March pay application invoice, are we waiving our rights to anything still owed prior to that? They have paid March; but not February. If we sign the waiver for March, do we have any lien rights for our February billing?
You should not be signing an unconditional waiver if you have not been paid. The waiver should be conditional.
For the conditional waiver, indicate on the waiver what money you are owed in addition to that being claimed in the waiver.
Retain a construction attorney to evaluate your legal situation and to provide advice.
Good luck.