The IRS is generally required to send you a notice before levying or seizing your property. You may be able to prevent a levy by timely requesting a Collection Due Process (CDP) hearing, and negotiating a payment plan or otherwise contesting the levy. You have 30 days from the date of the notice to request a CDP hearing.
There are situations where the IRS is not required to send you a pre-levy notice, and can take your property without giving you a chance to contest the levy. State tax refunds can be taken without notice, and the IRS can levy without notice if they believe that collection of the tax is in jeopardy.
There are also other situations where you may not get the chance to contest the levy until after your property has been seized. The IRS sends notices to your last known address, and you may never receive these notices if the IRS does not have your current address. You may also simply be unaware of your CDP rights or the 30-day deadline, and miss your chance to request a CDP hearing. Payroll taxes are also subject to different rules.