To improve bandwidth efficiency, multicast is used for mobile IPTV services. However, conventional multicast employs the most robust (lowest rate) modulation and coding scheme (MCS) for all multicasting channels to ensure that all users in a cell can receive videos with acceptable quality, leading to the worst spectral efficiency. To improve spectral efficiency, the adaptive MCS multicasting (aMCSm) scheme, which dynamically adjusts the MCS of each multicasting channel according to channel users' received signal-to-noise ratios (SNRs), was proposed. In this paper, the blocking rate, dropping rate, and bandwidth usage of mobile IPTV services under the aMCSm and the proposed admission control mechanism were analyzed based on a Markovian queueing model. The proposed mathematical model considers adaptive modulation and coding (AMC), time-varying link characteristics, channel popularity, and channel switching behavior. Numerical results demonstrate that our mathematical analyses are accurate and the aMCSm achieves better blocking rate and bandwidth usage performance, compared with the conventional multicast and multi-partition multicast schemes. The impact of channel switching or MCS variation on the performance of mobile IPTV services was investigated as well.