2025-10-23T06:38:24-05:00 2024-12-31 Foundation Source 3333 New Hyde Park Rd Ste 406 New Hyde Park NY 11042 990PF 2024-01-01 136086299 Gustavus and Louise Pfeiffer Research Foundation % Foundation Source GUST 8008391754 Foundation Source 501 Silverside Rd Wilmington DE 198091377 Sarah SP McCarthy Secretary 8008391754 2025-10-13 true true Jeffrey D Haskell P01345770 8008391754 2024 2025-03-06 01:10:19Z X 19610601 X 0 X 21974 21974 417414 417414 1208565 1239729 1223261 1647953 1662649 34000 3400 30600 2218 0 0 2218 11250 0 0 11250 36000 39532 3953 35579 75467 616 70890 198467 7969 0 150537 651000 651000 849467 7969 0 801537 798486 1654680 0 493619 146325 146325 3617 113 113 17366269 19464163 19464163 17863505 19610601 19610601 96868 121148 96868 121148 X 17766637 19489453 17766637 19489453 17863505 19610601 17766637 798486 924330 19489453 19489453 Publicly-traded Securities 1239729 16468 1223261 1223261 1223261 23000 23000 23000 6488 0 17200 23688 X 0 688 688 false false false false false false false true true NY true false false false false true Foundation Source 8008391754 501 Silverside Road Suite 123 Wilmington DE 198091377 false false false false true false false false false false false false false false false false false false false false false false Kimberly Herold Alvarez Foundation Source 501 Silverside Rd Wilmington DE 198091377 Dir 1.0 5200 0 0 Lise P Chapman Foundation Source 501 Silverside Rd Wilmington DE 198091377 Dir, Pres 1.0 7200 0 0 Patricia R Herold Foundation Source 501 Silverside Rd Wilmington DE 198091377 Dir, AS Sec, AS TREAS 1.0 7200 0 0 Matthew Mayro Keeney Foundation Source 501 Silverside Rd Wilmington DE 198091377 Dir, VP 1.0 7200 0 0 Sarah SP McCarthy Foundation Source 501 Silverside Rd Wilmington DE 198091377 Dir, Sec, Treas 1.0 7200 0 0 Foundation Source 55 Walls Drive 3rd Fl Fairfield CT 06824 Administrative 69458 18701305 556009 0 19257314 0 19257314 288860 18968454 948423 948423 23000 23000 925423 925423 925423 801537 0 0 0 0 801537 925423 1701080 1807348 4663416 86170 8258014 801537 801537 0 123886 123886 8134128 0 1577194 6556934 1807348 4663416 86170 NONE X HUNTINGTON MEDICAL RESEARCH INSTITUTES 686 S FAIR OAKS AVE PASADENA CA 91105 N/A PC To name the Imaging Core located in Room 332 as the "H. Robert Herold II Imaging Core" 500000 OLD MILL FOUNDATION 1120 OLD MILL RD SAN MARINO CA 91108 N/A PC General & Unrestricted 1000 PFEIFFER UNIVERSITY PO BOX 960 MISENHEIMER NC 28109 N/A PC Milton C. Rose Research Scholars 150000 651000 14 21974 14 417414 18 1208565 1647953 1647953 false false false false false false false false false false Audit Fees 11250 11250 VANGUARD BALANCED INDEX FUND I 6679247 6679247 VANGUARD WELLINGTON ADMIRAL FU 12784916 12784916 General Consultations 2218 2218 Administrative Fees 69876 69458 INSURANCE EXPENSE 4106 616 510 Registered Agent Fee 452 452 State or Local Filing Fees 50 50 Storage Fee 840 420 WEBSITE HOSTING/SUPPORT 143 UNREALIZED GAINS ON INVESTMENTS 924330 990-PF TAX FOR 2024 23000 INCREASE DEFERRED EXCISE TAX 13000