IRS Commissioner Danny Werfel has announced that the IRS is going after 1,600 millionaires who owe at least $250,000 each and collectively owe hundreds of millions of dollars, as part of an expanded push to make sure that wealthy taxpayers pay what they owe.

Time to start thinking about optimizing Roth conversions, RMDs, capital gains, Medicare premiums and charitable giving before year's end. The things you do before Dec. 31 are typically what save you the bigger dollars. And saving bigger dollars is fun for everyone. Here are five things retirees should consider before Dec. 31:

Last year, millions of taxpayers never responded to letters from the Internal Revenue Service requesting that they authenticate their identity before the IRS can release their federal income tax refunds, according to a new blog by the National Taxpayer Advocate.

Tax tips on TikTok and other social media can be helpful. But when a tax strategy sounds too good to be true, it should give you pause even if—or perhaps especially if—a post, reel, or clip is circulated widely. Going viral doesn't mean it's any more valuable. In some instances, those numbers may be artificially bumped as they’re shared by tax professionals to point out the flaws—as happened recently on X, formerly known as Twitter, in a thread discussing the infamous Augusta Rule.

Here’s a good bet: Millions of fans of online sports gambling have no idea they’re racking up big tax bills on their wagers—at least as the Internal Revenue Service sees it. Sports betting has exploded since 2018, when the Supreme Court struck down a national ban, and it’s now legal in 37 states and the District of Columbia.

The home sale exclusion remains one of the biggest and best tax breaks on the books. If a married couple filing jointly qualifies, they can exclude from tax up to a half million dollars of their profit when they sell their principal residence. However, you must meet certain requirements spelled out in the tax law. Significantly, the exclusion may be jeopardized if a couple is getting divorced.