The ADEA standards apply to age discrimination. The ADEA prohibits requiring people to work in a discriminatorily hostile or abusive environment. … The standards for assessing a hostile work environment claim under the ADEA are analogous to those utilized under [Title VII]. … Thus, the ADEA is violated when the workplace is permeated with discriminatory intimidation, ridicule, and insult … that is sufficiently severe or pervasive to alter the conditions of the victim’s employment and create an abusive working environment.

Citation: Murtha v. New York State Gaming Commission et al, 17-cv-10040, 2019 WL 4450687 (S.D.N.Y. Sept. 17, 2019)

This is non-trivial standard to meet, especially if all your evidence is "they called me a boomer".

> It is unlawful to harass a person because of his or her age.

> Harassment can include, for example, offensive or derogatory remarks about a person's age. Although the law doesn't prohibit simple teasing, offhand comments, or isolated incidents that aren't very serious, harassment is illegal when it is so frequent or severe that it creates a hostile or offensive work environment or when it results in an adverse employment decision (such as the victim being fired or demoted).

Seems to depend on how severe the behavior is.