There is no free parking in DC. And they close at a certain time so be aware.
Not free
Capital One Arena SpotHero Parking Page
There are a number of pay garages with a short walk. Pay attention to when they close, though.
It's available, and charged. You can reserve spots ahead of time, too.
Parking is available but there is a charge. If you can walk a block there is parking as low as $10. The parking under the arenas is $40. There are apps available that will let you know where and even get a discount for parking.
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