The fifth season of the American fictional drama television series ER first aired on September 24, 1998, and concluded on May 20, 1999.

Elizabeth Corday begins her surgical internship all over again in order to keep her job at the hospital, and ends her relationship with fellow surgeon Peter Benton.

While on probation after performing a risky procedure during the fourth season, Ross breaks protocol again by informing a mother how to alter the medication given to her disabled son.

Fourth season producer Penny Adams and co-producers Wendy Spence Rosato, Richard Thorpe, and Michael Salamunovich all returned to their roles.

Producers Wells, Woodward, Flint, Baer, Orman, Corbin, and Greene continued to write episodes.

Regular writer and previous technical advisor Joe Sachs was promoted to story editor for the fifth season and contributed to two episodes.

Regular directors Lesli Linka Glatter, Félix Enríquez Alcalá, and Rod Holcomb all returned to direct further episodes.

Other returning directors include executive producer John Wells, Christopher Misiano, David Nutter, and T.R.

After one more confrontation with the father of Joi's dead son, Ross makes a decision regarding his status at County—and his future in Chicago.