You'll need to find out from the plan whether this contribution made you covered for 2023 or instead for 2024. You are an active participant for a particular year if additions were made to your account in the retirement plan for the plan year ending with or within the particular year. If the plan uses a calendar year and the employer contribution made in early 2024 was for 2023, the contribution made you covered for 2023. If the plan instead uses a fiscal year, the addition in early 2024 likely makes you covered for 2024.
