Chapter 8 - Pre-Trial Resolution
8.200 Release, settlement and severance agreements
8.220 Validity of settlement agreements
8.223 OWBPA

29 U.S.C. § 626(f)(1)(A)-(H) explains the requirements necessary for a waiver of ADEA claims to be knowing and voluntary:

(f) Waiver

(1) An individual may not waive any right or claim under this chapter unless the waiver is knowing and voluntary. Except as provided in paragraph (2), a waiver may not be considered knowing and voluntary unless at a minimum --

(A) the waiver is part of an agreement between the individual and the employer that is written in a manner calculated to be understood by such individual, or by the average individual eligible to participate;

(B) the waiver specifically refers to rights or claims arising under this chapter;

(C) the individual does not waive rights or claims that may arise after the date the waiver is executed;

(D) the individual waives rights or claims only in exchange for consideration in addition to anything of value to which the individual already is entitled;

(E) the individual is advised in writing to consult with an attorney prior to executing the agreement;

(i) the individual is given a period of at least 21 days within which to consider the agreement; or

(ii) if a waiver is requested in connection with an exit incentive or other employment termination program offered to a group or class of employees, the individual is given a period of at least 45 days within which to consider the agreement;

(G) the agreement provides that for a period of at least 7 days following the execution of such agreement, the individual may revoke the agreement, and the agreement shall not become effective or enforceable until the revocation period has expired;

(H) if a waiver is requested in connection with an exit incentive or other employment termination program offered to a group or class of employees, the employer (at the commencement of the period specified in subparagraph (F)) informs the individual in writing in a manner calculated to be understood by the average individual eligible to participate, as to --

(i) any class, unit, or group of individuals covered by such program, any eligibility factors for such program, and any time limits applicable to such program; and

(ii) the job titles and ages of all individuals eligible or selected for the program, and the ages of all individuals in the same job classification or organizational unit who are not eligible or selected for the program.

(2) A waiver in settlement of a charge filed with the Equal Employment Opportunity Commission, or an action filed in court by the individual or the individual's representative, alleging age discrimination of a kind prohibited under section 623 or 633a of this title may not be considered knowing and voluntary unless at a minimum --

(A) subparagraphs (A) through (E) of paragraph (1) have been met; and

(B) the individual is given a reasonable period of time within which to consider the settlement agreement.

(3) In any dispute that may arise over whether any of the requirements, conditions, and circumstances set forth in subparagraph (A), (B), (C), (D), (E), (F), (G), or (H) of paragraph (1), or subparagraph (A) or (B) of paragraph (2), have been met, the party asserting the validity of a waiver shall have the burden of proving in a court of competent jurisdiction that a waiver was knowing and voluntary pursuant to paragraph (1) or (2).

(4) No waiver agreement may affect the Commission's rights and responsibilities to enforce this chapter. No waiver may be used to justify interfering with the protected right of an employee to file a charge or participate in an investigation or proceeding conducted by the Commission.