Millions of qubits need to be employed in a quantum computer to achieve a fault-tolerant quantum operation. To reduce the complexity in such a large-scale system, the control and readout circuitries have been proposed to be placed at the 4 K stage of dilution refrigerators [1]. CMOS technology is commonly used to leverage its scaling to enable large integration of control and readout circuitries with qubits. However, the high-fidelity readout operations require low noise amplifiers (LNAs) with a noise temperature of a few Kelvins. This necessitates the usage of HEMT and parametric amplifiers [2]. Recently reported CMOS LNAs are still far away from attaining such good performance [3-5]. Thus, this is one of the greatest challenges on the way to the fully integrated CMOS readout. Additionally, due to the limited cooling power of dilution refrigerators, low-power solutions are needed for achieving a very good noise performance at 4 K. This paper presents a 28 nm CMOS LNA for qubit readout, which achieves an order of magnitude power reduction compared to its CMOS counterparts while still providing a similar good noise Figure (NF) performance at 4 K.