This market will resolve to "Yes" if the United States government issues a measure banning entry into the United States by Russian nationals or by travelers who have been physically present in Russia or any specified region within Russia, on plague-related grounds between market creation and December 31, 2026, 11:59 PM ET. Otherwise, this market will resolve to "No". A qualifying measure is a proclamation, executive order, rule, or equivalent formal action that prohibits or suspends entry into US territory by Russian citizens or nationals, or by travelers who have been physically present in Russia or any specified region within Russia, whatever lookback period the measure uses. Russian nationality or physical presence in Russia or a specified region within Russia must be an express criterion determining who is subject to the entry prohibition. A measure that bars entry of Russian nationals as a class or travelers with such physical presence qualifies even if it carries exceptions or applies only to certain visa categories. The measure, or the official announcement issuing it, must cite plague, Yersinia pestis, or the suspected plague incident reported from Irkutsk Oblast, Russia in October 2026 as a basis for the entry prohibition. Plague need not be the sole basis, but a passing reference in background material is insufficient. A measure that cites no plague-related basis does not qualify. A statement of intent to impose a ban, with no formal measure issued, does not qualify. A measure that only limits, pauses, or slows visa processing or issuance without barring entry does not qualify, nor do sanctions, visa revocations, or entry denials targeting named individuals or entities. Testing, screening, quarantine, vaccination, or health-document requirements alone do not qualify. Restrictions based solely on an individual's infection, symptoms, or exposure, without a qualifying Russia-specific class prohibition, do not qualify. Travel advisories and measures that only restrict flights or boarding without prohibiting entry do not qualify. A measure already in force at market creation does not qualify. However, a new amendment to an existing measure qualifies if it introduces a qualifying plague-related entry prohibition. Merely adding a plague-related rationale to an unchanged existing prohibition does not qualify. Resolution turns on the date the measure is issued, not the date it takes effect or the date it is reported. A measure issued within the window counts even if its effective date falls later, its confirmation is reported afterward, or its implementation is halted or delayed by judicial or other action. The primary resolution source for this market will be official information from the US federal government; however, a consensus of credible reporting may also be used.