**Yes—generally, you can keep contributing to a 2040 target-date fund after 2040**, provided it remains available and you’re still eligible to contribute to the account holding it. The year guides the investment strategy; it isn’t an expiration date or a deadline to retire.

After 2040, the fund follows its planned investment mix:

- A **“to retirement”** fund generally stops becoming more conservative at the target date.
- A **“through retirement”** fund continues gradually shifting toward a more conservative mix afterward.

Neither automatically cashes you out when the target year arrives. See the [SEC’s explanation of target-date funds](https://www.investor.gov/introduction-investing/general-resources/news-alerts/alerts-bulletins/investor-bulletins/target-date-funds-investor-bulletin). Some providers eventually merge older funds into a retirement-income fund; [Vanguard’s prospectus](https://personal1.vanguard.com/pub/Pdf/p308.pdf), for example, describes this possibility.

**For retirement around 2043, a 2045 fund is a reasonable starting choice.** Within the same fund series, it will generally hold more stocks for longer than the 2040 fund, offering more growth potential with more volatility. The 2040 fund may suit you better if you prefer a more conservative allocation or expect to start withdrawing around 2040.

Compare the actual stock/bond mix, how it changes over time, and fees—not just the year. Your tolerance for losses and when you’ll need the money matter more than getting the date exactly right. The [SEC bulletin](https://www.investor.gov/introduction-investing/general-resources/news-alerts/alerts-bulletins/investor-bulletins/target-date-funds-investor-bulletin) also emphasizes those factors. You can revisit the choice as your retirement plans become clearer.