That depends on your Onset Date of Disability. Typically Medicare begins 29 months after your Onset Date. This includes the 5 month waiting period between your Onset Date and the start of your SSDI payments and then another 24 months of receiving those payments before your Medicare begins. (For those with ALS or ESRD, your Medicare benefits will begin as soon as your SSDI payments begin)
If you were determined to be disabled as of January 15, 2024, the 5 month waiting period would put your first SSDI payment on July 1, 2024. Then 24 months later, on July 1, 2026, your Medicare coverage would become effective. (If your Onset Date was determined to be on the 1st day of the month, that month can be counted in your 5 month waiting period)