Vanderplate Calvin

Vanderplate Calvin, doing business as Calvin Vanderplate PHD Abpp, a sole proprietorship based in Atlanta, Georgia, provides psychiatric and psychological medical consultant services to the Social Security Administration as a prime contractor, conducting independent disability case reviews and medical file evaluations for the agency's Atlanta regional office. The vendor operates exclusively on full-and-open competition with no set-aside designations across its federal footprint, though one historical award carried a Total Small Business set-aside designation.

Vanderplate Calvin's entire customer base consists of the Social Security Administration, which accounts for 48 awards (91% of the vendor's award count) and $8.9 million in combined potential value out of the vendor's $10.2 million total federal portfolio. The vendor has held a sustained single-agency relationship with SSA since at least 2005, operating entirely within the Atlanta Medical Consultants Contract vehicle and related SSA BPAs. The vendor sits on five parent BPAs and indefinite delivery contracts with SSA: Blanket Purchase Agreement 28321321AC0440023 (9 task orders, $1.7 million combined potential value), Blanket Purchase Agreement SS041140065 (14 task orders, $1.2 million), Blanket Purchase Agreement SS04164C009 (12 task orders, $1.3 million), Indefinite Delivery Contract SS040560004 (4 task orders, $1.2 million), and Indefinite Delivery Contract SS041060013 (5 task orders, $345 thousand). Recent work includes BPA call orders valued at $291,180 (awarded July 1, 2026, ultimate completion June 30, 2027), $242,650 (awarded February 7, 2025), and $116,472 (awarded March 6, 2026), all for regional medical consultant services supporting disability determination.

The vendor's capability portfolio is narrowly specialized: 38 of 53 awards fall under NAICS Offices of Physicians, Mental Health Specialists, with 41 awards coded to the Medical—Medical/Psychiatric Consultation PSC. Work scope centers on reviewing complex medical documentation, conducting independent case assessments, and providing psychiatric and psychological expertise to inform SSA disability claims decisions. Award activity has remained modest and flat over the past five years—one award in 2022, one in 2023, two in 2024, two in 2025, and two in 2026—with $6.1 million in combined dollars obligated to date (59% of combined potential value). Two awards carrying a combined potential value of $408 thousand reach ultimate completion within the next twenty-four months. The vendor holds no subcontractor relationships and operates exclusively as a prime, maintaining a specialized niche consultancy position with a single federal customer.