Below are the requirements I found for the Mac version (posted 12/10/18). You can also run the PC version if you also have Windows installed on your Mac. Some people find it more stable and more users available for support.
QuickBooks for Mac 2019 (applies to US only)
Minimum system requirements
- At least macOS 10.12 (Sierra); supported by macOS 10.13 (High Sierra), macOS 10.14 (Mojave)
- Intel processor, Core 2 Duo or higher
- Multiuser Server: Intel Core 2 Duo or higher processor to run server
- 2 GB RAM (4 GB RAM recommended)
- 250 MB of available disk space
- CD/DVD drive or Internet connection for downloaded installation
- Printer: 100% Macintosh-compatible printer, if you plan to print invoices, checks, deposit slips, lists, purchase orders, mailing labels, reports, or graphs
- Checks: Use Intuit Checks if you plan to print checks. Canadian Image Ready Checks are not supported
- Product registration required
