Yes, I read that as a lifetime maximum also. As shown on the 5695 instructions (2016) - <a rel="nofollow" target="_blank" href="
https://www.irs.gov/pub/irs-prior/i5695--2016.pdf">https://www.irs.gov/pub/irs-prior/i5695--2016.pdf...>
- A total combined credit limit of $500 for all tax years after 2005.
- A combined credit limit of $200 for windows for all tax years after 2005.
