Will I need to disclose a $79 profit on selling stocks while retired

It depends. If the stock sale was inside of a retirement account then it would be taxed when you receive distributions as retirement.  

If it was from your financial holdings outside of a retirement account, then you must include the stock sale profit in your income regardless of your age.

To enter your sale in TurboTax, follow these steps. Click this link for more information. Where do I enter Investment Sales?

1. Open or continue your return.
2. Navigate to the investment sales section:
   • TurboTax Online/Mobile: Go to investment sales. If using this application, make sure it is open
   • TurboTax Desktop: Search for investment sales and then select the Jump to link. 
     • Or Personal Tab > Continue > I'll choose what I work on > Scroll to Investment Income > Select Stocks, Cryptocurrency, Mutual Funds, Bonds, Other
3. Answer Yes to the question Did you sell any of these investments in 2024? (or Okay! to Time to kickoff your investments!).
   • If you land on  the Investment sales summary or Your investments and savings screen, select Add More Sales or Add investments.