The Geisinger MyCode Community Health Initiative research project strives to understand population level genomics by pairing electronic health records (EHR) with genomic data. More than 295,000 participants are enrolled and >184,000 participants have paired exome and EHR data available, known as the DiscovEHR cohort. Within this broader initiative, the MyCode Genomic Screening and Counseling program (GSC) facilitates screening for and disclosure of genomic findings expected to increase disease risk, as well as evaluating the clinical and healthcare impact of those results. The currently included genes/diseases are based on recommendations from the American College of Medical Genetics and Genomics (ACMG) for return of secondary findings (SF). With the recent expansion of the ACMG SF list, we sought to understand the potential impact of including these new genes for population genomic screening with respect to the interpretive and clinical burden of identifying and disclosing results within a rural healthcare system. In May of 2021, version three (v3.0) of the ACMG SF list was released, comprising a total of 73 genes related to cancer (28), cardiovascular (33), metabolic (4), and miscellaneous diseases (8). We evaluated the 14 newly added genes (PALB2, MAX, TMEM127, FLNC, CASQ2, TRDN, TTN, BTD, GAA, HFE - p.Cys282Tyr homozygotes only, ACVRL1, ENG, HNF1A, and RPE65) for inclusion in the MyCode GSC program focusing on the gene-disease relationships, actionability scores, prevalence, and penetrance estimates. We identified high quality (allele balance ≥30, depth ≥20, and genotype quality ≥80) sequence variants in the newly added genes and filtered by predicted molecular consequence (eg, predicted truncating variants, missense variants, and splice variants) and ClinVar classification and star status (≥2* pathogenic (P), likely pathogenic (LP), or equivalent), excluding common benign variants (>1% minor allele frequency (MAF) within MyCode, >1% MAF in gnomAD, or >3% MAF if ClinVar 3*). Filtered variants underwent a high-level manual review (as previously described) to identify variants expected to be P or LP. The new genes on the SF v3.0 list have similar actionability assertions and gene-disease validities as the v2.0 genes currently returned by MyCode. We screened 144,204 MyCode participants and identified 330 unique P/LP variants in 686 participants across the 8 dominant genes and 10 unique variants in 6 participants from 3 of the recessive genes (BTD, GAA, and RPE65). Addition of these results increases our screen positive rate from 2.1-2.6% to 2.6-3.1%, an increase of 19-24%. This increase is predominantly due to truncating variants in A-band of TTN, accounting for 71.5% (n=236) of the returnable variants and 66.0% (n=453) of the new screen positive results. The next largest contributor was PALB2 at 15.2% (n=50) of returnable variants and 20.1% (n=138) of new screen positive results. The third largest was FLNC with 6.1% (n=20) returnable variants and 5.5% (n=38) of the new screen positive results. The remaining genes contributed less than 3% to both variants and screen positive results. As anticipated, the 14 new ACMG SF genes are similar in terms of actionability assertions and gene-disease validities to the 59 genes included in the prior version. We estimate a 19-24% increase in screen positive results compared to ACMG SF v2.0 by including these new genes in population screening programs, with the vast majority coming from TTN. Importantly, a screen positive result is not synonymous with a genetic diagnosis due to the influence of reduced penetrance and variable expressivity, which are not well understood in the context of population screening.