Where do I enter Form 5498-SA?

Menu Path: Deductions/Credits > Other Deductions/Credits > Health Savings Account (HSA) (1099-SA)

Form 5498-SA reports your annual Health Savings Account (HSA) contributions to the IRS. If all your HSA contributions were made through your employer, it should all be included on your W-2 Box 12, Code W. If you made additional contributions on your own, outside payroll, enter them on the Health Savings Account screen.

Can I make contributions to my HSA after the end of the year?