First, any time you are offered a severance agreement that includes signing a release of claims, you should consult with an employment lawyer to better understand whether you have legal claims against your employer that may be worth more than what they are offering you.
Second, the federal Age Discrimination in Employment Act (ADEA) and related laws and regulations include specific requirements for a release of age discrimination claims to be effective. These include:
You must be given 21 days to consider the agreement before signing
Once you sign, you must be given a seven-day period in which you have the right to revoke, or cancel, the agreement
If your termination is part of a layoff or reorganization, the employer must disclose to you by department, role and age, which employees were and were not included in the layoff. This document can be confusing to read, but the intent is to allow you or your lawyer to assess whether older workers were disproportionately affected by the layoff or reorganization.