HCPC codes update quarterly. There's a new file January, April, July, and October of every year. You can keep up on quarterly HCPC updates each year on the CMS website:
https://www.cms.gov/medicare/coding-billing/healthcare-common-procedure-system/quarterly-update
The HCPC books are based on the January file, which is typically available from CMS mid-December each year. That's why HCPC books don't ship out until mid-January each year - it takes some time to publish the print books after CMS makes the file available in mid-December.
CPT is copyrighted by the AMA. There's generally not a complete list made public without purchasing the data or the book.
However, you can usually find some summaries, articles, and webinars about the new year's CPT code set written by either the AMA or by industry professionals who have purchased the books or code sets and written articles about changes they have found.
For 2026, there are 418 code changes: 288 new codes, 84 deleted codes, and 46 revised codes. (According to a press release from the AMA:
https://www.ama-assn.org/press-center/ama-press-releases/ama-releases-cpt-2026-code-set )
It looks like AAPC has a 2026 CPT updates webinar scheduled for November 25, presented by Rae Jimenez. Additionally, Rae will have an article in the December issue of AAPC the Magazine. (According to this AAPC article:
https://www.aapc.com/blog/93398-ama-releases-cpt-2026/ )
You can probably find other vendors who are also doing CPT 2026 update sessions and articles to summarize the changes.
But as far as a downloadable list of CPT changes, AMA does not publish that for free. You either have to get a book, subscribe to an encoder, or purchase a data download.