iMac (Retina 5K, 27-inch, Mid 2015)
Our verdict
Revive it.
Apple’s updates ended on macOS Big Sur 11. The community’s didn’t.
I
Give it a new OS
OpenCore Legacy Patcher runs macOS Tahoe 26 on this machine — a modern browser and current patches, unofficially. OpenCore Legacy Patcher ↗
II
Give it a job
A single-purpose desk machine — music, photos, a second screen with history.
III
Or let it go
Apple parts availability is winding down (vintage status). Trade-in value is modest — selling privately usually beats the quote.
VintageTops out at macOS Big Sur 11 — or macOS Tahoe 26 with OpenCore.
The record
Introduced
2015
Model identifier
iMac15,1
Chip
Intel Core i5/i7 Haswell
Architecture
Intel
Latest official release
macOS Big Sur 11
With OpenCore Patcher
macOS Tahoe 26 · official patcher site
Security updates
Ended — macOS Big Sur received its final security update in 2023 (last release 11.7.10 (2023-09-11)).
Apple hardware status
Vintage — parts winding down
Data confidence
high, sources disagree (see footnotes)
Common questions
What is the newest macOS for the iMac (Retina 5K, 27-inch, Mid 2015)?
The iMac (Retina 5K, 27-inch, Mid 2015) officially tops out at macOS Big Sur 11. The community’s OpenCore Legacy Patcher can take it to macOS Tahoe 26, unofficially.
Is the iMac (Retina 5K, 27-inch, Mid 2015) still getting security updates?
No. Ended — macOS Big Sur received its final security update in 2023 (last release 11.7.10 (2023-09-11)).
Can the iMac (Retina 5K, 27-inch, Mid 2015) run a newer macOS than Big Sur 11?
Officially, no. Unofficially, yes: OpenCore Legacy Patcher runs macOS Tahoe 26 on this machine — a modern browser and current patches. It’s unsupported territory, so back up first.
Is the iMac (Retina 5K, 27-inch, Mid 2015) vintage or obsolete?
Apple classifies it as vintage: parts and service are winding down but may still be available.
The fine print
a
The identifier iMac15,1 is also used by the iMac (Retina 5K, 27-inch, Late 2014). Same identifier, different support ceilings — check the year before trusting a lookup.
b
task1_mac_models.csv (Apple support pages) says macOS Big Sur 11 · mac_models_main.csv (gemini export) says macOS Monterey 12. We use: macOS Big Sur 11.
c
Multi-cycle model identifier reuse says The Late 2014 iMac15,1 model officially maxes out at macOS Big Sur 11, whereas the Mid…. We use: Identifier-to-model mapping disambiguated by release year in this database..
Same shelf