Under governing US Supreme Court cases, 1983 actions are precluded when based on federal statutes if those statutes contain comprehensive remedial schemes.  However, federal statutes do not foreclose 1983 actions based on constitutional guarantees if the statutory rights and protections diverge significantly from the constitutional ones.  Here, the 9th Circuit concludes that an ADEA action for retaliation diverges significantly enough from a 1983 action based on deprivation of First Amendment rights (due to retaliation for volunteering to testify in an another employee’s ADEA suit) so that the ADEA remedy does not foreclose the 1983 remedy.  Different parties may sue and be sued:  The ADEA does not allow suit against individuals or state entities, whereas 1983 does.  The ADEA allows suit only by employees; 1983 allows suit by independent contractors.  The ADEA applies to private employers; 1983 does not.  Under the ADEA, the plaintiff must prove retaliation was a but-for cause of the adverse employment action; whereas, under 1983 it is enough for the plaintiff to show it was a motivating factor in causing the adverse action.  The 1983 action also allows additional consequential damage remedies.

Ninth Circuit Court of Appeals (Friedland, J.; Fernandez, J., dissenting); August 5, 2016; 2016 WL 4151221