Jason Chaffetz will be absent from Congress for 3 to 4 weeks for 'immediate' foot surgery

— -- House Oversight Committee Chairman Jason Chaffetz will be out of commission for up to four weeks as he heads back to his home state of Utah for "immediate foot surgery," he announced in an Instagram post Wednesday night.

The Republican congressman's absence from Washington means that he will miss a key vote on a spending bill to keep the government open, according to The Associated Press.

"Almost 12 years ago, I shattered several bones in my foot which required 14 screws and a metal plate to repair," Chaffetz explains in his post, alongside an X-ray of his foot. "Yes, I wish I could say I was cliff diving in Mexico but the truth is I fell off a ladder while repairing something in my garage."

He continues, "The University of Utah doctors now recommend immediate surgery to remove all the hardware or I could be at risk for serious infection. My recovery is expected to take three to four weeks."

Chaffetz, 50, acknowledges now isn't the best time to be absent from the nation's capital. "I'm sorry to miss the important work we are doing in Washington," he writes. "This is not an opportune time to be away but medical emergencies are never convenient. I appreciate my constituent's patience and understanding as I take time to recover."

Chaffetz's announcement comes a week after he revealed that he will not run for re-election in 2018.

"After long consultation with my family and prayerful consideration, I have decided I will not be a candidate for any office in 2018," he wrote in an April 19 Facebook post.

He didn't close the door on politics, though, writing, "I may run again for public office, but not in 2018. For those that would speculate otherwise, let me be clear that I have no ulterior motives. I am healthy. I am confident I would continue to be re-elected by large margins. I have the full support of Speaker Ryan to continue as Chairman of the Oversight and Government Reform Committee. That said, I have made a personal decision to return to the private sector."

ABC News' Benjamin Siegel contributed to this report.