If you are going for cashless hospitalization, then you must speak to your hospital’s insurance desk. They will send a cashless pre-authorization (pre-auth) request to your insurance company or TPA (Third-party administrator). A pre-auth request can be sent any time before the day of admission or on the day of admission.
In case you are not getting cashless, then you have the option to go for a reimbursement claim. Ideally, you must send an intimation to the insurer before getting admitted. Intimation can be done online by visiting the website of the insurer or TPA. You can also call the customer care number of the insurer or TPA to inform them regarding your claim.
While not every insurer or TPA makes it mandatory to intimate regarding the claim, some of them can hold your claim and raise a query regarding reasons for non-intimation of the claim. Therefore it is always better to intimate regarding the claim before you submit the reimbursement claim.