Incapacity Benefit is being replaced with Employment and Support Allowance (ESA).
If you're already claiming Incapacity Benefit you'll be reassessed to decide if you're capable of work or eligible for ESA. You won't be reassessed if you're close to State Pension Age.
If your reassessment shows you're capable of working, your Incapacity Benefit will stop. If your reassessment shows you can't work, you'll be automatically transferred onto ESA.