This is a mirror of the tip on https://discussions.apple.com/docs/DOC-13695 stored to retain the original formatting after the communities formatting change of 2018.
It is maintained on my website, which may get compensation for me.
The table below includes the Machine ID/Model Identifier, that comes from the System Profiler, found under Apple menu -> About This Mac -> System Report -> Hardware.
This shows the upgrade paths up to Mojave for all Intel Macs, and their Model Identifiers. Note the horizontal scrollbar on the bottom of this tip to show the Mac Pro compatibility is beyond the width of this tip's layout.
Every Mac released on or after an operating system release can't run an older version of Mac OS. The one exception is Mac OS X 10.6 Server which can run on Parallels on newer Macs. For more on release dates, see the identifying articles are found on this tip:
How to find your Mac's model and age?
|10.6 compatible - 10.6.8||MacBook 1,1||iMac 4,x||MacBook Pro 1,x||Mac Mini 1,x|
|10.6.3 to 10.7.5 compatible||MacBook with removable battery||iMac 5,x; 6,x||MacBook Pro 2,x||Mac Mini 2,x||MacBook Air 1,x||Mac Pro 1,x-2,x|
|10.8 - 10.11 preloaded with 10.4||Late 2008 MacBook Aluminum 5,1||iMac Mid 2007 7,1||mid 2007 MacBook Pro 3,1 - 4,2|
|10.8 -10.11 preloaded with 10.5||MacBook White Early 2009 5,2||iMac Early 2008 8,1, 9,1||MacBook Pro 5,1 - 6,2||
early 2009 3,1
|MacBook Air Late 2008 2,1||Mac Pro Early 2008 3,1 and 4,1|
|10.12 & 10.13* compatible with 10.6.3 retail. Also 10.11 compatible through 10.6.8 App Store.||MacBook Late 2009 6,1||iMac Late 2009 10,1 and 11,1|
|10.12 & 10.13* compatible with system specific 10.6.3 or later||MacBook 7,1 Mid 2010||iMac 11,2 Mid-2010||MacBook Pro mid-2010 7,1||
Mid 2010 4,1
|MacBook Air Late 2010 3,1|
|Mac Pro 5,1 (2010)|
|10.12, 10.14, and 10.15 compatible
(original shipping OS)
MacBook early 2015 8,1
|iMac Late 2012 12,1
(Shipped with 10.8.2)**
|MacBook Pro Mid-2012 9,1
Late 2012 6,1
MacBook Air Mid 2012 5,1
Mac Pro 2013 9,1
* Note starting with 10.13, Apple introduced APFS that made reading newer systems on older Macs that don't support Mac OS 10.13 invisible. This is especially a problem on formatted SSDs as those would automatically format in the new system. Older platter hard drives could retain the HFS+ GUID formatting on the newer operating systems to allow older systems to see the new systems in target disk mode.
** Catalina machines that shipped with 10.8.5 or earlier need to be upgraded to 10.12 first before being able to upgrade to Catalina.