Severance and unemployment, do they overlap? after 16 years as a web developer

My employer is paying severance in instalments and I am not sure whether to file now. The agreement mentions a release and a payment schedule. Who should I ask before signing?

Some states only count certain kinds of severance. A local workforce centre could tell me which.

Rules differ by state. I called the claims line and asked directly, then wrote down the answer and the date.