Asked for sources supporting their assumption of 15% downstream care claims cost reduction, the authors of Healthcare Innovations in Georgia — Anderson Economic Group and Wilson Partners (AEG/WP) — point to Nextera’s contract with DigitalGlobe, as reported in Nextera’s self-published study here.
And here’s the exact table from that study showing claims cost reductions for DPC members.

That’s a overall claims cost reduction of $71.98 per month.
The AEG/WP report assumes a $70 PMPM direct primary care fee (which seems to be unrealistically low). Even at $70 a month, the Nextera experience suggests that we should expect net cost reductions of $2 PMPM.
That’s less than 4% of the net cost reductions of $53 developed in AEG/WP’s analysis. A conservative approximation, based on Nextera’s reported experience, indicates that AEG/WP’s prediction of $21.5 million dollar first year savings in the individual market is off by $20.8 million dollars.