The suspension will take effect at the start of the 1995-96 season.
"Although Mr. Pivonka has not previously faced supplementary discipline for this type of conduct, there can be no excuse for the reckless manner in which he struck and injured Mr. Samuelsson with his stick," said Brian Burke, NHL senior vice president.
The incident occurred at 5:15 of the second period. Pivonka was immediately assessed a major penalty for high sticking and a game misconduct. Samuelsson required more than 60 stitches to close wounds to his chin and mouth.
Pivonka is out of town and could not be reached for comment, but Washington general manager David Poile voiced disappointment.
"There were so many things that happened in the course of that series," said Poile. "That play was something that was a reflex action in the course of the game.
"I asked [the league] to review the play in which [Francois] Leroux intentionally slashed the back of Keith Jones' legs, but they're not going to do anything about that.
"There was nothing intentional about [Pivonka's action] and the penalty doesn't seem fair or equitable."
The Capitals announced that prices for season tickets and partial-plan tickets will remain unchanged for fans who renew their tickets or who purchase new season or partial plans before Aug. 1.
Prices will range from $10 to $35 per ticket for those who opt to purchase them in the next two months.
Gate and revised season-ticket prices will be announced later this summer.