The IRS has issued proposed regulations that would make it easier to deduct “local lodging” costs — in other words, staying overnight when not away from home. The new rules provide a safe harbor for certain local lodging at a business meeting, conference, or other activity or function. Other local lodging expenses may be deductible as business expenses depending on the facts and circumstances. Although these rules will officially take effect when final regulations are published, the IRS says taxpayers can rely on them now, including on returns that have already been filed but for which the statute of limitations for claiming a refund has not expired (generally returns for years 2009 or later).
Resource: Proposed regulation in the Federal Register (PDF)

