The NextGen Model Atmosphere grid covers effective temperatures from 3000 K to 10000 K, with log(g) ranging from 3.5 to 5.5 and metallicities from -4.0 to 0.0. It includes LTE models for low-mass stars and is the basis for future NLTE models. The grid uses the same assumptions as the VLMS part of NextGen, allowing consistent stellar evolution and spectral analysis. Models were calculated using PHOENIX code with direct opacity sampling, including molecular line data from HITRAN92 and updated CO and CN line lists. The grid includes detailed molecular opacities and updated equation of state (EOS) data. Comparisons with Kurucz 92 models show good agreement for temperatures above 5000 K, with differences due to abundance variations and opacity sampling methods. NLTE effects are significant for temperatures above 7000 K, requiring detailed NLTE models for accurate results. The grid is available for download and includes synthetic spectra and model structures. The paper discusses the importance of NLTE effects for solar-type and Vega-like stars, showing that LTE models are less accurate for higher effective temperatures. The study concludes that NLTE effects are crucial for temperatures above 7000 K, and LTE models are only valid in a narrow range near solar-type stars. The work was supported by various grants and institutions, and the results are compared with observational data and other models.The NextGen Model Atmosphere grid covers effective temperatures from 3000 K to 10000 K, with log(g) ranging from 3.5 to 5.5 and metallicities from -4.0 to 0.0. It includes LTE models for low-mass stars and is the basis for future NLTE models. The grid uses the same assumptions as the VLMS part of NextGen, allowing consistent stellar evolution and spectral analysis. Models were calculated using PHOENIX code with direct opacity sampling, including molecular line data from HITRAN92 and updated CO and CN line lists. The grid includes detailed molecular opacities and updated equation of state (EOS) data. Comparisons with Kurucz 92 models show good agreement for temperatures above 5000 K, with differences due to abundance variations and opacity sampling methods. NLTE effects are significant for temperatures above 7000 K, requiring detailed NLTE models for accurate results. The grid is available for download and includes synthetic spectra and model structures. The paper discusses the importance of NLTE effects for solar-type and Vega-like stars, showing that LTE models are less accurate for higher effective temperatures. The study concludes that NLTE effects are crucial for temperatures above 7000 K, and LTE models are only valid in a narrow range near solar-type stars. The work was supported by various grants and institutions, and the results are compared with observational data and other models.